MFC r325614:

MFC r325614:
Multiple fixes for using IPv6 link-local addresses with RDMA.

1) Fail to resolve RDMA address if rtalloc1() returns the loopback
device, lo0, as the gateway interface.

2) Use ip_dev_find() and ip6_dev_find() to lookup network interfaces
with matching IPv4 and IPv6 addresses, respectivly.

3) In addr_resolve() make sure the "ifa" pointer is always set, also when
the "ifp" is NULL. Else a NULL pointer access might happen trying to
read from the "ifa" pointer later on.

Sponsored by:	Mellanox Technologies

git-svn-id: svn://svn.freebsd.org/base/stable/10@325940 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f