Qt: make playlist font less small by default

(cherry picked from commit 987c2953afaed2217e012ba02e3221b7d2963d27)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/components/playlist/playlist_model.cpp

@@ -372,7 +372,7 @@ QVariant PLModel::data( const QModelIndex &index, const int role ) const
     else if( role == Qt::FontRole )
     {
         QFont f;
-        f.setPointSize( __MAX( f.pointSize() - 1 + i_zoom, 4 ) );
+        f.setPointSize( __MAX( f.pointSize() + i_zoom, 4 ) );
         if( isCurrent( index ) )
             f.setBold( true );
         return QVariant( f );