fix edit flag doesn't get reset, causing AV in edit menu

stepmania/src/EditCoursesMenu.cpp

@@ -79,8 +79,6 @@ EditCoursesMenu::EditCoursesMenu()
 {
 	LOG->Trace( "ScreenEditCoursesMenu::ScreenEditCoursesMenu()" );
 
-	GAMESTATE->m_bEditing = true;
-
 	m_bInSongMenu = false;
 
 	for( int i=0; i<2; i++ )

stepmania/src/ScreenEdit.cpp

@@ -1508,6 +1508,9 @@ void ScreenEdit::HandleScreenMessage( const ScreenMessage SM )
 		m_pSteps = GAMESTATE->m_pCurSteps[PLAYER_1];
 
 		SCREENMAN->SetNewScreen( "ScreenEditMenu" );
+
+		GAMESTATE->m_bEditing = false;
+
 		break;
 	case SM_BackFromMainMenu:
 		HandleMainMenuChoice( (MainMenuChoice)ScreenMiniMenu::s_iLastLine, ScreenMiniMenu::s_iLastAnswers );