feat: remove memory leak when calling QLayout::replaceWidget

Author: lievenhey

src/callgraphwidget.cpp

@@ -42,7 +42,8 @@ CallgraphWidget::CallgraphWidget(Data::CallerCalleeResults results, KParts::Read
         generateCallgraph(m_currentSymbol);
     });
 
-    layout()->replaceWidget(ui->graphPlaceholder, view->widget());
+    auto oldWidget = layout()->replaceWidget(ui->graphPlaceholder, view->widget());
+    delete oldWidget;
 
     updateColors();
     m_interface->setLayoutMethod(KGraphViewer::KGraphViewerInterface::LayoutMethod::InternalLibrary);

src/frequencypage.cpp

@@ -51,7 +51,8 @@ FrequencyPage::FrequencyPage(PerfParser* parser, QWidget* parent)
 
     m_page->setupUi(this);
 
-    m_page->layout->replaceWidget(m_page->plotWidget, m_plot);
+    auto oldWidget = m_page->layout->replaceWidget(m_page->plotWidget, m_plot);
+    delete oldWidget;
 
     auto plotData = QSharedPointer<PlotData>::create();