layers: GH877, Clear up descriptor state messages
layers: GH877, Clear up descriptor state messages

Plumbed function name through for more descriptive error
messages from validate_and_update_drawtime_descriptor_state().

Change-Id: I109e14e07e6a5ba29c45dc3e0ad075ff3575d67f

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