Fixed pageLayout, pageSize, pageOrientation, pageMargins for QPdfWriter

Task-number: QTBUG-46887
Change-Id: I8f1497a8b7ff13213879de01fcdfcabfdd471874
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

src/gui/painting/qpdfwriter.cpp

@@ -151,7 +151,8 @@ QPdfWriter::QPdfWriter(const QString &filename)
   Constructs a PDF writer that will write the pdf to \a device.
   */
 QPdfWriter::QPdfWriter(QIODevice *device)
-    : QObject(*new QPdfWriterPrivate)
+    : QObject(*new QPdfWriterPrivate),
+      QPagedPaintDevice(new QPdfPagedPaintDevicePrivate(d_func()))
 {
     Q_D(QPdfWriter);