anv/radv: clear color attachment assertion
Following up a misunderstanding on !186 (merged) I've also opened an issue on the validation layer : https://github.com/KhronosGroup/Vulkan-ValidationLayers/issues/678
Following up a misunderstanding on !186 (merged) I've also opened an issue on the validation layer : https://github.com/KhronosGroup/Vulkan-ValidationLayers/issues/678