[PATCH] md: bio leak fix

insert a missing bio_put when writting the md superblock.

Without this we have a steady growth in the "bio" slab.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3802f7a..4a0c57d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -338,6 +338,7 @@
 
 	if (atomic_dec_and_test(&rdev->mddev->pending_writes))
 		wake_up(&rdev->mddev->sb_wait);
+	bio_put(bio);
 	return 0;
 }