smb: client: destroy cfid_put_wq on module exit

Fix potential problem in rmmod

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/client/cifsfs.c

@@ -2043,6 +2043,7 @@ exit_cifs(void)
 	destroy_workqueue(decrypt_wq);
 	destroy_workqueue(fileinfo_put_wq);
 	destroy_workqueue(serverclose_wq);
+	destroy_workqueue(cfid_put_wq);
 	destroy_workqueue(cifsiod_wq);
 	cifs_proc_clean();
 }