Bug Fix: Corrected result check in test dEQP-VK.api.command_buffers.submit_null_fence
Added queueWaitIdle on the end of the test. Not working fence and exit without waiting for the queue could affect others tests.
Validation errors are described in [Issue 357](https://github.com/KhronosGroup/Vulkan-LoaderAndValidationLayers/issues/357).
See merge request !528