block: fix inconsistent parenthesisation of QUEUE_FLAG_DEFAULT

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d08c4b8..dcaa0fd 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -455,7 +455,7 @@
 
 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
 				 (1 << QUEUE_FLAG_CLUSTER) |		\
-				  1 << QUEUE_FLAG_STACKABLE)
+				 (1 << QUEUE_FLAG_STACKABLE))
 
 static inline int queue_is_locked(struct request_queue *q)
 {