[locale] Reduce API surface

- getLocationPosition doesn't need to be a method, since it calls out
  to a static function of TimeZoneImageList anyway.

src/modules/locale/timezonewidget/timezonewidget.cpp

@@ -34,6 +34,13 @@
 #define ZONE_NAME QStringLiteral( "zone" )
 #endif
 
+static QPoint
+getLocationPosition( const CalamaresUtils::Locale::TZZone* l )
+{
+    return TimeZoneImageList::getLocationPosition( l->longitude(), l->latitude() );
+}
+
+
 TimeZoneWidget::TimeZoneWidget( QWidget* parent )
     : QWidget( parent )
     , timeZoneImages( TimeZoneImageList::fromQRC() )

src/modules/locale/timezonewidget/timezonewidget.h

@@ -53,11 +53,6 @@ private:
     TimeZoneImageList timeZoneImages;
     const TZZone* m_currentLocation = nullptr;  // Not owned by me
 
-    QPoint getLocationPosition( const TZZone* l )
-    {
-        return timeZoneImages.getLocationPosition( l->longitude(), l->latitude() );
-    }
-
     void paintEvent( QPaintEvent* event );
     void mousePressEvent( QMouseEvent* event );
 };