Fix iv_wait on QNX 6.5.0.
Fix iv_wait on QNX 6.5.0.

By not using wait4(2), which doesn't return events for some reason
(and since there are no man pages on the QNX machine I have access
to, I can't figure out why).

Signed-off-by: Lennert Buytenhek <8858498612e3a522354216649776e3032dcb7e5b@wantstofly.org>

buytenh/ivykis,buytenh/ivykis