MFC r325436: RTF_PINNED for an interface
Allow a process to assign an IP address to local ppp interface
even if kernel routing table already has a route to the address in question
installed by some routing daemon (PR 223129).
Also, allow loopback route deletion when stopping a VIMAGE jail (PR 222647).
PR: 222647, 223129
Reviewed by: gnn
Approved by: mav (mentor)
Differential Revision: https://reviews.freebsd.org/D12747
git-svn-id: svn://svn.freebsd.org/base/stable/10@326012
ccf9f872-aa2e-dd11-9fc8-
001c23d0bc1f