layers: Fix 32-bit compilation warnings/errors introduced last night.
layers: Fix 32-bit compilation warnings/errors introduced last night.

Several 32-bit compilation warnings and errors were introduced into
draw_state.cpp last night.  This fixes those issues and allows our builds
to work again.

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