Get rid of superfluous whitespace on the right side of thumbnails when

using a QStyle with SH_ScrollView_FrameOnlyAroundContents, by using the 
viewport's width.

svn path=/trunk/KDE/kdegraphics/okular/; revision=746443

ui/thumbnaillist.cpp

@@ -429,7 +429,7 @@ void ThumbnailList::viewportResizeEvent( QResizeEvent * e )
         delayedRequestVisiblePixmaps( 2000 );
 
         // resize and reposition items
-        int newWidth = contentsRect().width() - verticalScrollBar()->width();
+        int newWidth = viewport()->width();
         int newHeight = 0;
         QVector<ThumbnailWidget *>::const_iterator tIt = m_thumbnails.begin(), tEnd = m_thumbnails.end();
         for ( ; tIt != tEnd; ++tIt )