vulkan/wsi/x11: Smplify implementation of vkGetPhysicalDeviceSurfaceFormatsKHR
vulkan/wsi/x11: Smplify implementation of vkGetPhysicalDeviceSurfaceFormatsKHR

This patch simplifies x11_surface_get_formats(). It is actually just a
readability improvement over the patch I provided earlier this week
(750d8cad72).

Reviewed-by: Eric Engestrom <de0b63cf2dfb1fae8ed3c3b4244856a05677d4f0@imgtec.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler