ImageViewer: Don't blur the ImageViewer background pattern on HighDpi

Simply don't draw the background pattern with interpolated scaling.

Task-number: QTCREATORBUG-22280
Change-Id: Iae17f4ce663ae82ee00cbebaa9830b5bb86d5735
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/imageviewer/imageview.cpp

@@ -151,6 +151,7 @@ void ImageView::drawBackground(QPainter *p, const QRectF &)
 {
     p->save();
     p->resetTransform();
+    p->setRenderHint(QPainter::SmoothPixmapTransform, false);
     p->drawTiledPixmap(viewport()->rect(), backgroundBrush().texture());
     p->restore();
 }