layers:Fix CmdDispatch post-call function
layers:Fix CmdDispatch post-call function

Cut-and-paste bug was incorrectly calling CmdDraw post-call function
instead of CmdDispatch.

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