Convert audit_log() call to WARN_ONCE().

Rename "type=" to nlmsg_type=" to avoid confusion with the audit record
type.

Added "protocol=" to help track down which protocol (NETLINK_AUDIT?) was used
within the netlink protocol family.
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
[Rewrote the patch subject line]
Signed-off-by: NPaul Moore <pmoore@redhat.com>