ssh: apply style(9) to version_addendum

Reported by: allanjude (in review D29953)
Fixes: 462c32cb8d7a ("Upgrade OpenSSH to 6.1p1.")
MFC after: 1 week
Sponsored by: The FreeBSD Foundation

(cherry picked from commit 613b4b79713e294140757270f02a8aa6273be3d4)