blk-mq: rename mq_flush_work struct request member

We will use this work_struct to requeue scsi commands from the
completion handler as well, so give it a more generic name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 95bb551..7128808 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -98,7 +98,7 @@
 	struct list_head queuelist;
 	union {
 		struct call_single_data csd;
-		struct work_struct mq_flush_work;
+		struct work_struct requeue_work;
 		unsigned long fifo_time;
 	};