GetNextScreen -> GetNextScreenName (makes return type more clear in Lua)

stepmania/src/ScreenOptions.cpp

@@ -533,7 +533,7 @@ void ScreenOptions::HandleScreenMessage( const ScreenMessage SM )
 			m_sNextScreen = sThisScreen;
 
 		// If options set a NextScreen or one is specified in metrics, then fade out
-		if( GetNextScreen() == "" )
+		if( GetNextScreenName() == "" )
 		{
 			LOG->Warn( "%s::HandleScreenMessage: Tried to fade out, but we have no next screen", m_sName.c_str() );
 			return;