scripts:Account for extnumber key to fix warnings
scripts:Account for extnumber key to fix warnings

With the addition of the 'extnumber' key update comparison to skip over
the extnumber as well as extname in order to avoid a bunch of
irrelevant warnings.

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