loader: Removed some unnecessary code.
loader: Removed some unnecessary code.

Now that all WSI paths need the ICD structs, I can get rid of
a code path no longer used.

Change-Id: Ib5073cd2074fcd66453dae5b6c89870c81f7f958

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