dm writecache: interrupt writeback if suspended

If the DM device is suspended, interrupt the writeback sequence so
that there is no excessive suspend delay.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-writecache.c

@@ -1844,8 +1844,9 @@ restart:
 
 		n_walked++;
 		if (unlikely(n_walked > WRITEBACK_LATENCY) &&
-		    likely(!wc->writeback_all) && likely(!dm_suspended(wc->ti))) {
+		    likely(!wc->writeback_all)) {
-			queue_work(wc->writeback_wq, &wc->writeback_work);
+			if (likely(!dm_suspended(wc->ti)))
+				queue_work(wc->writeback_wq, &wc->writeback_work);
 			break;
 		}