fix canvas issues from previous commit

examples/RenderingExamples/TinyVRGui.cpp

@@ -28,7 +28,7 @@ struct TestCanvasInterface2 : public Common2dCanvasInterface
 
 	virtual ~TestCanvasInterface2() 
 	{}
-	virtual int createCanvas(const char* canvasName, int width, int height)
+	virtual int createCanvas(const char* canvasName, int width, int height,int posX,int posY)
 	{
 		return 0;
 	}