msg_types.h: Don't use strncmp for comparing sockaddr_in.

Fixes: #8472
Signed-off-by: Dan Mick <dan.mick@inktank.com>
Merge pull request #1888 from ceph/wip-8472

msg_types.h: Don't use strncmp for comparing sockaddr_in.

Reviewed-by: Loic Dachary <loic@dachary.org>