layers:Separate two error checks
layers:Separate two error checks

There's separate valid usage language for VkPushConstantRange size
being non-zero and being multiple of 4. Breaking the validation
callbacks to flag these two errors separately along with their
respective unique error enums.

KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers