cubepp: Fix VK_KHR_display compile error
cubepp: Fix VK_KHR_display compile error

Vulkan-Hpp Implicit-cast operators on vk::ResultValue were previously
deprecated and finally removed in the v1.3.213 headers. Fix the
resulting compiler error in cubepp by explicitly using the value member
of vk:ResultValue.

Change-Id: Ie441bd56dfb9dfe26e966e0ec3fb3139712a351a

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools