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
Differential Revision: https://reviews.freebsd.org/D28673

(cherry picked from commit 9fdbf7eef5c006002769add15b1ebb8fa8d9e220)