MFC r285642

MFC r285642

ssh: canonicize the host name before looking it up in the host file

Re-apply r99054 by des in 2002. This was accidentally dropped
by the update to OpenSSH 6.5p1 (r261320).

This change is actually taken from r387082 of
ports/security/openssh-portable/files/patch-ssh.c

Differential Revision: https://reviews.freebsd.org/D3103
PR:             198043
Approved by:    kib (mentor)
Sponsored by:   Dell Inc.
Relnotes:       yes

git-svn-id: svn://svn.freebsd.org/base/stable/9@285763 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f