fix deprecation warnings (followup 5f86422)

Author: jef-n

src/core/symbology-ng/qgsrulebasedrendererv2.cpp

@@ -980,7 +980,7 @@ bool QgsRuleBasedRendererV2::legendSymbolItemsCheckable() const
 bool QgsRuleBasedRendererV2::legendSymbolItemChecked( const QString& key )
 {
   Rule* rule = mRootRule->findRuleByKey( key );
-  return rule ? rule->checkState() : true;
+  return rule ? rule->active() : true;
 }
 
 void QgsRuleBasedRendererV2::checkLegendSymbolItem( const QString& key, bool state )

src/gui/symbology-ng/qgsrulebasedrendererv2widget.cpp

@@ -861,7 +861,7 @@ QVariant QgsRuleBasedRendererV2Model::data( const QModelIndex &index, int role )
   {
     if ( index.column() != 0 )
       return QVariant();
-    return rule->checkState() ? Qt::Checked : Qt::Unchecked;
+    return rule->active() ? Qt::Checked : Qt::Unchecked;
   }
   else
     return QVariant();