Ensure FMODE_NONOTIFY is not set by userspace

    In fsnotify_open() ensure that FMODE_NONOTIFY is never set by userspace.
    Also always call fsnotify_parent and fsnotify.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>