rbd: don't bother checking whether order changes

When a format 2 image is refreshed, code is in place to verify that
the object order never changes from what it was originally.  This
relies on the fact that the refresh will occur *after* an initial
load of information about the image.

An upcoming patch makes it possible for the refresh to occur first,
so we can no longer make this order check.  The order really can't
ever change anyway--this was just a sanity check.  So get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

drivers/block/rbd.c

@@ -4024,20 +4024,12 @@ static char *rbd_dev_snap_info(struct rbd_device *rbd_dev, u32 which,
 static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev, u64 *hver)
 {
 	int ret;
-	__u8 obj_order;
 
 	down_write(&rbd_dev->header_rwsem);
 
-	/* Grab old order first, to see if it changes */
-
-	obj_order = rbd_dev->header.obj_order,
 	ret = rbd_dev_v2_image_size(rbd_dev);
 	if (ret)
 		goto out;
-	if (rbd_dev->header.obj_order != obj_order) {
-		ret = -EIO;
-		goto out;
-	}
 	rbd_update_mapping_size(rbd_dev);
 
 	ret = rbd_dev_v2_snap_context(rbd_dev, hver);