rds: simplify a warning message

Cc: David S. Miller <davem@davemloft.net>
Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/rds/message.c

@@ -82,10 +82,7 @@ static void rds_message_purge(struct rds_message *rm)
 void rds_message_put(struct rds_message *rm)
 {
 	rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
-	if (atomic_read(&rm->m_refcount) == 0) {
-printk(KERN_CRIT "danger refcount zero on %p\n", rm);
-WARN_ON(1);
-	}
+	WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
 	if (atomic_dec_and_test(&rm->m_refcount)) {
 		BUG_ON(!list_empty(&rm->m_sock_item));
 		BUG_ON(!list_empty(&rm->m_conn_item));