iv_signal: Don't call sigaction() with SA_RESTART on QNX.
iv_signal: Don't call sigaction() with SA_RESTART on QNX.

QNX does define a value for SA_RESTART, but any attempts to register
a signal handler with SA_RESTART set result in -ENOTSUP.

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

buytenh/ivykis,buytenh/ivykis