dm: reduce the queue delay used in dm_request_fn from 100ms to 10ms

Commit 7eaceac ("block: remove per-queue plugging") didn't justify
DM's use of a 100ms delay; such an extended delay is a liability when
there is reason to re-kick the queue.

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

drivers/md/dm.c

@@ -1997,7 +1997,7 @@ static void dm_request_fn(struct request_queue *q)
 	goto out;
 
 delay_and_out:
-	blk_delay_queue(q, HZ / 10);
+	blk_delay_queue(q, HZ / 100);
 out:
 	dm_put_live_table(md, srcu_idx);
 }