Add a comment to the software renderer that stride should be implemented

Source/Core/VideoBackends/Software/SWmain.cpp

@@ -203,6 +203,9 @@ void VideoSoftware::Video_Prepare()
 // Run from the CPU thread (from VideoInterface.cpp)
 void VideoSoftware::Video_BeginField(u32 xfbAddr, u32 fbWidth, u32 fbStride, u32 fbHeight)
 {
+	// XXX: fbStride should be implemented properly here
+	// If stride isn't implemented then there are problems with XFB
+	// Animal Crossing is a good example for this.
 	s_beginFieldArgs.xfbAddr = xfbAddr;
 	s_beginFieldArgs.fbWidth = fbWidth;
 	s_beginFieldArgs.fbHeight = fbHeight;