smb: client: fix incomplete backport in cfids_invalidation_worker()

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix incomplete backport in cfids_invalidation_worker() The previous commit bdb596ceb4b7 ("smb: client: fix potential UAF in smb2_close_cached_fid()") was an incomplete backport and missed one kref_put() call in cfids_invalidation_worker() that should have been converted to close_cached_dir().