bcache: use op_is_sync to check for synchronous requests

(and remove one layer of masking for the op_is_write call next to it).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index 301eaf5..629bd1a 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -57,8 +57,7 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
 	if (would_skip)
 		return false;
 
-	return bio->bi_opf & REQ_SYNC ||
-		in_use <= CUTOFF_WRITEBACK;
+	return op_is_sync(bio->bi_opf) || in_use <= CUTOFF_WRITEBACK;
 }
 
 static inline void bch_writeback_queue(struct cached_dev *dc)