Fixed a couple of issues reported by cppcheck.

src/cantor_part.cpp

@@ -339,8 +339,6 @@ CantorPart::CantorPart( QWidget *parentWidget, QObject *parent, const QVariantLi
     connect(removeCurrent, &QAction::triggered, m_worksheet, &Worksheet::removeCurrentEntry);
     m_editActions.push_back(removeCurrent);
 
-    Cantor::Backend* const backend = Cantor::Backend::getBackend(backendName);
-
     // Disabled, because uploading to kde store from program don't work
     // See https://phabricator.kde.org/T9980 for details
     // If this situation will changed, then uncomment this action
@@ -750,6 +748,7 @@ void CantorPart::showBackendHelp()
     auto* job = new KIO::OpenUrlJob(backend->helpUrl());
     job->setUiDelegate(new KIO::JobUiDelegate(KJobUiDelegate::AutoHandlingEnabled, widget()));
     job->start();
+    delete job;
 }
 
 Worksheet* CantorPart::worksheet()

src/latexentry.h

@@ -38,7 +38,7 @@ class LatexEntry : public WorksheetEntry
     QJsonValue toJupyterJson() override;
     QString toPlain(const QString& commandSep, const QString& commentStartingSeq, const QString& commentEndingSeq) override;
 
-    void layOutForWidth(qreal w, qreal entry_zone_x, bool force = false) override;
+    void layOutForWidth(qreal entry_zone_x, qreal w, bool force = false) override;
 
     int searchText(const QString& text, const QString& pattern,
                    QTextDocument::FindFlags qt_flags);

src/worksheet.cpp

@@ -1654,7 +1654,7 @@ bool Worksheet::loadJupyterNotebook(const QJsonDocument& doc)
     qDebug() << "loading jupyter entries";
 
     WorksheetEntry* entry = nullptr;
-    for (QJsonArray::const_iterator iter = cells.begin(); iter != cells.end(); iter++) {
+    for (QJsonArray::const_iterator iter = cells.begin(); iter != cells.end(); ++iter) {
         if (!Cantor::JupyterUtils::isJupyterCell(*iter))
         {
             QApplication::restoreOverrideCursor();