loader: Change overzealous warning to debug msg
loader: Change overzealous warning to debug msg

Change-Id: Idde5f8c8f009e365bdcf1fffaffa669d0557d66b

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