nbd: set queue timeout properly

We can't just set the timeout on the tagset, we have to set it on the
queue as it would have been setup already at this point.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index dbc22f4..b0003da 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -844,7 +844,10 @@
 		nbd_size_set(nbd, bdev, nbd->blksize, arg);
 		return 0;
 	case NBD_SET_TIMEOUT:
-		nbd->tag_set.timeout = arg * HZ;
+		if (arg) {
+			nbd->tag_set.timeout = arg * HZ;
+			blk_queue_rq_timeout(nbd->disk->queue, arg * HZ);
+		}
 		return 0;
 
 	case NBD_SET_FLAGS: