ipfw: Retire obsolete compat code

[emaste]

Summary

The current IPFW version dates to 2010 (commit cc4d3c30ea28, "Bring in
the most recent version of ipfw and dummynet, developed").  We no longer
need backwards compatibility with FreeBSD 8 and earlier.

[markj]

There's a reference to IP_DUMMYNET_GET in sbin/ipfw/ipfw2.c that can probably be removed as well.

[emaste]

In D53343#1218208, @markj wrote:

There's a reference to IP_DUMMYNET_GET in sbin/ipfw/ipfw2.c that can probably be removed as well.

Fair point, D53348

[ae]

LGTM.

[glebius]

sys/modules/dummynet/Makefile

2–3

Maybe merge those SRCS declarations? At least first two into one line.

[emaste]

There's a reference to IP_DUMMYNET_GET in sbin/ipfw/ipfw2.c that can probably be removed as well.

Actually there's a bunch of unused cases in do_cmd() not just IP_DUMMYNET_GET -- D53378