Remove now-unused rt_ifp,rt_ifa,rt_gateway,rt_mtu rte fields.

[melifaro]

Summary

After converting routing subsystem customers to use nexthop objects defined in rS359823, some fields in struct rtentry became unused.

This commit removes rt_ifp, rt_ifa, rt_gateway and rt_mtu from struct rtentry along with the code, setting and updating these fields.

Test Plan

divert:ipdivert_ip6_output_remote_success  ->  passed  [2.772s]
forward6:fwd_ip6_gu_icmp_gw_gu_fast_success  ->  passed  [3.116s]
forward6:fwd_ip6_gu_icmp_gw_gu_slow_success  ->  passed  [2.382s]
forward6:fwd_ip6_gu_icmp_gw_ll_fast_success  ->  passed  [2.920s]
forward6:fwd_ip6_gu_icmp_gw_ll_slow_success  ->  passed  [2.653s]
forward6:fwd_ip6_gu_icmp_iface_fast_success  ->  passed  [2.672s]
forward6:fwd_ip6_gu_icmp_iface_slow_success  ->  passed  [2.704s]
mld:mldraw01  ->  passed  [3.783s]
output6:output6_raw_flowid_mpath_success  ->  skipped: This test requires ROUTE_MPATH enabled  [0.020s]
output6:output6_raw_success  ->  passed  [1.911s]
output6:output6_tcp_flowid_mpath_success  ->  skipped: This test requires ROUTE_MPATH enabled  [0.025s]
output6:output6_tcp_setup_success  ->  passed  [1.281s]
output6:output6_udp_flowid_mpath_success  ->  skipped: This test requires ROUTE_MPATH enabled  [0.020s]
output6:output6_udp_setup_success  ->  passed  [2.909s]
redirect:valid_redirect  ->  passed  [2.785s]
scapyi386:scapyi386  ->  passed  [3.825s]

divert:ipdivert_ip_input_local_success  ->  passed  [0.624s]
divert:ipdivert_ip_output_remote_success  ->  passed  [0.720s]
fibs_test:arpresolve_checks_interface_fib  ->  skipped: Required configuration property 'fibs' not defined  [0.001s]
fibs_test:default_route_with_multiple_fibs_on_same_subnet  ->  skipped: Required configuration property 'fibs' not defined  [0.004s]
fibs_test:default_route_with_multiple_fibs_on_same_subnet_inet6  ->  skipped: Required configuration property 'fibs' not defined  [0.001s]
fibs_test:loopback_and_network_routes_on_nondefault_fib  ->  skipped: Required configuration property 'fibs' not defined  [0.001s]
fibs_test:loopback_and_network_routes_on_nondefault_fib_inet6  ->  skipped: Required configuration property 'fibs' not defined  [0.002s]
fibs_test:same_ip_multiple_ifaces  ->  skipped: Required configuration property 'fibs' not defined  [0.002s]
fibs_test:same_ip_multiple_ifaces_fib0  ->  skipped: Required configuration property 'fibs' not defined  [0.002s]
fibs_test:same_ip_multiple_ifaces_inet6  ->  skipped: Required configuration property 'fibs' not defined  [0.003s]
fibs_test:slaac_on_nondefault_fib6  ->  skipped: Required configuration property 'allow_sysctl_side_effects' not defined  [0.004s]
fibs_test:subnet_route_with_multiple_fibs_on_same_subnet  ->  skipped: Required configuration property 'fibs' not defined  [0.002s]
fibs_test:subnet_route_with_multiple_fibs_on_same_subnet_inet6  ->  skipped: Required configuration property 'fibs' not defined  [0.002s]
fibs_test:udp_dontroute  ->  skipped: Required configuration property 'fibs' not defined  [0.002s]
fibs_test:udp_dontroute6  ->  skipped: Required configuration property 'fibs' not defined  [0.002s]
forward:fwd_ip_icmp_gw_fast_success  ->  passed  [0.756s]
forward:fwd_ip_icmp_gw_slow_success  ->  passed  [0.738s]
forward:fwd_ip_icmp_iface_fast_success  ->  passed  [0.720s]
forward:fwd_ip_icmp_iface_slow_success  ->  passed  [0.699s]
ip_reass_test:ip_reass__large_fragment  ->  passed  [0.014s]
ip_reass_test:ip_reass__multiple_last_fragments  ->  passed  [0.031s]
ip_reass_test:ip_reass__zero_length_fragment  ->  passed  [0.017s]
output:output_raw_flowid_mpath_success  ->  skipped: This test requires ROUTE_MPATH enabled  [0.025s]
output:output_raw_success  ->  passed  [0.074s]
output:output_tcp_flowid_mpath_success  ->  skipped: This test requires ROUTE_MPATH enabled  [0.018s]
output:output_tcp_setup_success  ->  passed  [0.128s]
output:output_udp_flowid_mpath_success  ->  skipped: This test requires ROUTE_MPATH enabled  [0.018s]
output:output_udp_setup_success  ->  passed  [1.205s]
redirect:valid_redirect  ->  passed  [0.773s]
so_reuseport_lb_test:basic_ipv4  ->  passed  [0.615s]
so_reuseport_lb_test:basic_ipv6  ->  passed  [0.729s]
socket_afinet:socket_afinet  ->  passed  [0.004s]
socket_afinet:socket_afinet_bind_ok  ->  passed  [0.002s]
socket_afinet:socket_afinet_bind_zero  ->  skipped: doesn't work when mac_portacl(4) loaded (bug238781)  [0.003s]

test_rtsock_l3:rtm_add_v4_gu_ifa_ordered_success  ->  passed  [0.008s]
test_rtsock_l3:rtm_add_v4_gw_direct_success  ->  passed  [0.007s]
test_rtsock_l3:rtm_add_v4_temporal1_success  ->  passed  [0.017s]
test_rtsock_l3:rtm_add_v6_gu_gw_gu_direct_success  ->  passed  [0.007s]
test_rtsock_l3:rtm_add_v6_gu_ifa_hostroute_success  ->  passed  [0.004s]
test_rtsock_l3:rtm_add_v6_gu_ifa_ordered_success  ->  passed  [0.007s]
test_rtsock_l3:rtm_add_v6_gu_ifa_prefixroute_success  ->  passed  [0.005s]
test_rtsock_l3:rtm_add_v6_temporal1_success  ->  passed  [0.006s]
test_rtsock_l3:rtm_del_v4_gu_ifa_prefixroute_success  ->  passed  [0.012s]
test_rtsock_l3:rtm_del_v4_prefix_nogw_success  ->  passed  [0.010s]
test_rtsock_l3:rtm_del_v6_gu_ifa_hostroute_success  ->  passed  [0.007s]
test_rtsock_l3:rtm_del_v6_gu_ifa_prefixroute_success  ->  passed  [0.019s]
test_rtsock_l3:rtm_del_v6_gu_prefix_nogw_success  ->  passed  [0.006s]
test_rtsock_l3:rtm_get_v4_empty_dst_failure  ->  passed  [0.003s]
test_rtsock_l3:rtm_get_v4_exact_success  ->  passed  [0.009s]
test_rtsock_l3:rtm_get_v4_hostbits_failure  ->  passed  [0.008s]
test_rtsock_l3:rtm_get_v4_lpm_success  ->  passed  [0.008s]
test_rtsock_lladdr:rtm_add_v4_gu_lle_success  ->  passed  [0.006s]
test_rtsock_lladdr:rtm_add_v6_gu_lle_success  ->  passed  [0.004s]
test_rtsock_lladdr:rtm_add_v6_ll_lle_success  ->  passed  [0.003s]
test_rtsock_lladdr:rtm_del_v4_gu_lle_success  ->  passed  [0.008s]
test_rtsock_lladdr:rtm_del_v6_gu_lle_success  ->  passed  [0.003s]
test_rtsock_lladdr:rtm_del_v6_ll_lle_success  ->  passed  [0.004s]