(PECL inotify >= 0.1.2)
inotify_rm_watch — Remove an existing watch from an inotify instance
$inotify_instance
   , int $watch_descriptor
   ) : bool
   inotify_rm_watch() removes the watch
   watch_descriptor from the inotify instance
   inotify_instance.
  
   成功时返回 TRUE, 或者在失败时返回 FALSE。