dm cache policy smq: put newly promoted entries at the top of the multiqueue

This stops entries bouncing in and out of the cache quickly.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-cache-policy-smq.c

@@ -1452,6 +1452,7 @@ static void __complete_background_work(struct smq_policy *mq,
 		clear_pending(mq, e);
 		if (success) {
 			e->oblock = work->oblock;
+			e->level = NR_CACHE_LEVELS - 1;
 			push(mq, e);
 			// h, q, a
 		} else {