*()(struct cn_msg *) prototype.  Change cn_ulog_callback to match it by
removing void * and adding struct cn_msg * directly.

It's introduced by commit:
connector: make callback argument type explicit
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>