If rfd is equal to wfd the file descriptor is closed but
rfd will still have the closed value.
The EventNotifier structure should not be used again after calling
event_notifier_cleanup or should be initialized again but make
sure to not have dandling file descriptors around.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20191023122652.2999-2-fziglio@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>