build: Fix CMake coding error
build: Fix CMake coding error

Need STREQUAL when compating strings.

Change-Id: Id65055d18af2c0bbd3e4959f21587e2ba9afa607

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