tests: Fix Windows build warning
tests: Fix Windows build warning

commit 2aa3d0a6fd6592fd54bbcf6aa1d064a2b8b758d3
removed all uses of `err`

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