layers: Indicate correct source for validateCommandBufferState() error
layers: Indicate correct source for validateCommandBufferState() error

Fixes #982

Instead of hard-coding vkQueueSubmit, take a parameter to clarify if the error
originates from vkQueueSubmit() or vkCmdExecuteCommands()

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