[PATCH] rq_for_each_bio fix

From: Xavier Bestel <xavier.bestel@free.fr>

Within the body of this macro we are accessing rq->bio, but `bio' is an arg
to the macro.  If someone uses this macro with some variable which is not
named `bio' it won't compile.

So use a more-likely-to-be-unique identifier for the macro.

include/linux/blkdev.h

@@ -483,9 +483,9 @@ static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
 }
 #endif /* CONFIG_MMU */
 
-#define rq_for_each_bio(bio, rq)	\
+#define rq_for_each_bio(_bio, rq)	\
 	if ((rq->bio))			\
-		for (bio = (rq)->bio; bio; bio = bio->bi_next)
+		for (_bio = (rq)->bio; _bio; _bio = bio->bi_next)
 
 struct sec_size {
 	unsigned block_size;