Make in_localip_more() fib-aware.

It fixes loopback route installation for the interfaces
in the different fibs using the same prefix.

Reviewed By: donner
PR: 189088
Approved by: re(gjb)
Differential Revision: https://reviews.freebsd.org/D28673

(cherry picked from commit f67641675958cb566b0ae50dc6942017d42393fe)