init_flush_request() only set REQ_FLUSH when initializing flush
requests making them READ requests.  Use WRITE_FLUSH instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
 static void init_flush_request(struct request *rq, struct gendisk *disk)
 {
        rq->cmd_type = REQ_TYPE_FS;
-       rq->cmd_flags = REQ_FLUSH;
+       rq->cmd_flags = WRITE_FLUSH;
        rq->rq_disk = disk;
 }