Fix warnings in qtbase.

Change-Id: I981e08872440e35eb9bfad32b20543cfce8439c9
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

src/gui/kernel/qwindow.cpp

@@ -736,9 +736,6 @@ void QWindow::setWindowState(Qt::WindowState state)
 void QWindow::setTransientParent(QWindow *parent)
 {
     Q_D(QWindow);
-
-    QWindow *previousParent = d->transientParent;
-
     d->transientParent = parent;
 }
 

src/printsupport/kernel/qprinterinfo_unix.cpp

@@ -847,6 +847,8 @@ QList<QPrinter::PaperSize> qt_getCupsPrinterPaperSizes(int cupsPrinterIndex)
         for (int j = 0; j < size->num_choices; ++j)
             result.append(string2PaperSize(size->choices[j].choice));
     }
+#else
+    Q_UNUSED(cupsPrinterIndex)
 #endif
     return result;
 }

src/widgets/itemviews/qdirmodel.cpp

@@ -1162,7 +1162,6 @@ QFileInfo QDirModel::fileInfo(const QModelIndex &index) const
 
 void QDirModelPrivate::init()
 {
-    Q_Q(QDirModel);
     filters = QDir::AllEntries | QDir::NoDotAndDotDot;
     sort = QDir::Name;
     nameFilters << QLatin1String("*");

src/widgets/kernel/qwidget.cpp

@@ -8441,6 +8441,7 @@ void QWidget::mouseReleaseEvent(QMouseEvent *event)
 
 void QWidget::mouseDoubleClickEvent(QMouseEvent *event)
 {
+    Q_UNUSED(event)
 }
 
 #ifndef QT_NO_WHEELEVENT