Cleaning: the QPalette is not needed outisde the constructor

The QPalette of the widget is already stored in QWidget, there is no
need to have an attribute for it.
Signed-off-by: Ilkka Ollakka <ileoo@videolan.org>

modules/gui/qt4/components/interface_widgets.cpp

@@ -299,7 +299,7 @@ BackgroundWidget::BackgroundWidget( intf_thread_t *_p_i )
 
     /* A dark background */
     setAutoFillBackground( true );
-    plt = palette();
+    QPalette plt = palette();
     plt.setColor( QPalette::Active, QPalette::Window , Qt::black );
     plt.setColor( QPalette::Inactive, QPalette::Window , Qt::black );
     setPalette( plt );

modules/gui/qt4/components/interface_widgets.hpp

@@ -42,7 +42,6 @@
 #include <QMouseEvent>
 
 class ResizeEvent;
-class QPalette;
 class QPixmap;
 class QHBoxLayout;
 class QMenu;
@@ -95,7 +94,6 @@ public:
     virtual ~BackgroundWidget();
 
 private:
-    QPalette plt;
     QLabel *label;
     virtual void contextMenuEvent( QContextMenuEvent *event );
     intf_thread_t *p_intf;