fusefs: fix a cached attributes bug during directory rename

When renaming a directory into a different parent directory, invalidate
the cached attributes of the new parent. Otherwise, stat will show the
wrong st_nlink value.

Reviewed by: ngie
Differential Revision: https://reviews.freebsd.org/D34336

(cherry picked from commit e8553be9bcfc2c0d78e9f379bd166dc0a9cae719)