layers:Refactor barrier validation

Migrate validation for renderpass barrier in CmdPipelineBarrier to its
own function. Refactor some device and command buffer params to avoid
duplicate look-ups. Add some const decls to command buffer state that
shouldn't change down the pre-call path.
diff --git a/layers/buffer_validation.h b/layers/buffer_validation.h
index a9b2b38..c10b337 100644
--- a/layers/buffer_validation.h
+++ b/layers/buffer_validation.h
@@ -118,7 +118,7 @@
 bool ValidateBarrierLayoutToImageUsage(layer_data *device_data, const VkImageMemoryBarrier *img_barrier, bool new_not_old,
                                        VkImageUsageFlags usage, const char *func_name);
 
-bool ValidateBarriersToImages(layer_data *device_data, VkCommandBuffer cmdBuffer, uint32_t imageMemoryBarrierCount,
+bool ValidateBarriersToImages(layer_data *device_data, GLOBAL_CB_NODE const *cb_state, uint32_t imageMemoryBarrierCount,
                               const VkImageMemoryBarrier *pImageMemoryBarriers, const char *func_name);
 
 void TransitionImageLayouts(layer_data *device_data, VkCommandBuffer cmdBuffer, uint32_t memBarrierCount,