msdosfs: fix directory corruption after rename operation
PR: 268005
Reviewed by: mckusick
Approved by: re (cperciva)
(cherry picked from commit 8b67c670a49b4efe7e1557121b5bbae682ea3bc7)
(cherry picked from commit 5f4753501e9cc59e0d15f849c9459478ea5c8dc7)