Added release function to PoolVector::Access.

For clarity, assign-to-release idiom for PoolVector::Read/Write
replaced with a function call.
Existing uses replaced (or removed if already handled by scope)

editor/editor_profiler.cpp

@@ -340,7 +340,7 @@ void EditorProfiler::_update_plot() {
 		}
 	}
 
-	wr = PoolVector<uint8_t>::Write();
+	wr.release();
 
 	Ref<Image> img;
 	img.instance();