layers: Fix script crash for special-cased err enum
layers: Fix script crash for special-cased err enum

Change-Id: Ic054c35fd777e66e85ed56978ad1628ec24b94a6

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