RDS: rds_message_unmapped() doesn't need to check if queue active

If the queue has nobody on it, then wake_up does nothing.
Signed-off-by: Andy Grover <andy.grover@oracle.com>

net/rds/message.c

@@ -406,7 +406,6 @@ void rds_message_wait(struct rds_message *rm)
 void rds_message_unmapped(struct rds_message *rm)
 {
 	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
-	if (waitqueue_active(&rds_message_flush_waitq))
 	wake_up(&rds_message_flush_waitq);
 }
 EXPORT_SYMBOL_GPL(rds_message_unmapped);