[SCSI] iscsi_tcp regression: remove bogus warn on in write path

An empty r2tqueue is a valid state. It just means that we have
processed all that there was to do. This patch removes the WARN_ON
that was added when the kfifo changes were merged.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/libiscsi_tcp.c

@@ -992,11 +992,9 @@ static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task)
 		if (r2t == NULL) {
 			if (kfifo_out(&tcp_task->r2tqueue,
 			    (void *)&tcp_task->r2t, sizeof(void *)) !=
-			    sizeof(void *)) {
-				WARN_ONCE(1, "unexpected fifo state");
+			    sizeof(void *))
 				r2t = NULL;
-			}
-
+			else
 				r2t = tcp_task->r2t;
 		}
 		spin_unlock_bh(&session->lock);