ext4: reuse order and buddy in mb_mark_used when buddy split

After each buddy split, mb_mark_used will search the proper order
for the block which may consume some loop in mb_find_order_for_block.
In fact, we can reuse the order and buddy generated by the buddy split.

Reviewed by: lei.rao@intel.com
Signed-off-by: hanjinke <hanjinke.666@bytedance.com>
Link: https://lore.kernel.org/r/20220606155305.74146-1-hanjinke.666@bytedance.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>