cube.c: Remove excess tests from presentation fences
cube.c: Remove excess tests from presentation fences

Instead of using a bool array and both checking and writing to it every frame for no reason, just create the presentation fences with the VK_FENCE_CREATE_SIGNALED_BIT flag.
KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools