blk-mq: properly drain stopped queues

If we need to drain a queue we need to run all queues, even if they
are marked stopped to make sure the driver has a chance to error out
on all queued requests.

This fixes surprise removal with scsi-mq.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Bart Van Assche <bvanassche@acm.org>

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e11f5f8..fd8b485 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -120,7 +120,7 @@
 
 		if (count == 0)
 			break;
-		blk_mq_run_queues(q, false);
+		blk_mq_start_hw_queues(q);
 		msleep(10);
 	}
 }