Fix mq.notify = nil to unregister notifications

"mq.notify = false" also works now, doing what
"mq.notify = nil" used to do (using SIGEV_NONE).

I was confused by SIGEV_NONE usage vs using a NULL pointer for
the notification passed mq_notify(3).  SIGEV_NONE does not
actually unregister, it registers a no-op notification which
prevents other processes from taking us.

This also fixes the test case to pass under both Linux and
FreeBSD.

0 files changed, 0 insertions, 0 deletions