Qt: Fix zooming with mouse wheel in game list (#3549)

Author: Pesa

src/duckstation-qt/gamelistwidget.cpp

@@ -1784,7 +1784,7 @@ void GameListListView::wheelEvent(QWheelEvent* e)
     const int dy = e->angleDelta().y();
     if (dy != 0)
     {
-      adjustIconSize((dy < 0) ? ICON_SIZE_STEP : ICON_SIZE_STEP);
+      adjustIconSize((dy < 0) ? -ICON_SIZE_STEP : ICON_SIZE_STEP);
       return;
     }
   }