layers:Only deref active subpass once
layers:Only deref active subpass once

Grab active subpass once initially to avoid repeated defers of cb_state

KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers