md: change type of first arg to sync_page_io.

Currently sync_page_io takes a 'bdev'.
Every caller passes 'rdev->bdev'.
We will soon want another field out of the rdev in sync_page_io,
So just pass the rdev instead of the bdev out of it.

Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/bitmap.c

@@ -212,7 +212,7 @@ static struct page *read_sb_page(mddev_t *mddev, loff_t offset,
 
 		target = rdev->sb_start + offset + index * (PAGE_SIZE/512);
 
-		if (sync_page_io(rdev->bdev, target,
+		if (sync_page_io(rdev, target,
 				 roundup(size, bdev_logical_block_size(rdev->bdev)),
 				 page, READ)) {
 			page->index = index;