The QProcessunixProcessParameters sometimes fails in CI with an XPASS.
Unclear under what conditions QNX behaves correctly, so accept that it
is unpredictable and only expect a failure when a failure is imminent.
Amends f9c87cfd44.
Change-Id: Icf70861343747e6323c7953a2462b7bbc46549b3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>