update vulkan.h for multi-level command buffers (V121)

With minimal changes to keep everything building and functioning.
diff --git a/tests/layer_validation_tests.cpp b/tests/layer_validation_tests.cpp
index 59acc4f..4b8addb 100644
--- a/tests/layer_validation_tests.cpp
+++ b/tests/layer_validation_tests.cpp
@@ -211,7 +211,7 @@
     VkResult result;
 
     if (renderPass()) {
-        cmdBuffer.EndRenderPass(renderPass());
+        cmdBuffer.EndRenderPass();
     }
 
     result = cmdBuffer.EndCommandBuffer();