[PATCH] md: initialise sync_blocks in raid1 resync

Otherwise it could have a random value and might BUG.  This fixes a BUG
during resync problem in raid1 introduced by the bitmap-based-intent-loggin
patches.
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/md/raid1.c

@@ -1230,6 +1230,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
 	}
 
 	nr_sectors = 0;
+	sync_blocks = 0;
 	do {
 		struct page *page;
 		int len = PAGE_SIZE;