Minor: add helpers lastFailedUpdateStep() and setLastFailedUpdateStep().

UpdatePTUDevCtrl/worker.h

@@ -231,6 +231,7 @@ class Worker : public QThread{
     int sendUpdateSucceededAndActivated();
     int sendFinalResult();
 
+public:
     struct UpdateProcessRunning {
         Worker *m_worker;
 
@@ -395,6 +396,14 @@ protected:
     virtual void run();
 
 public:
+    UPDATE_STEP lastFailedUpdateStep() const {
+        return m_lastFailedUpdateStep;
+    }
+
+    void setLastFailedUpdateStep(UPDATE_STEP step) {
+        m_lastFailedUpdateStep = step;
+    }
+
     QDebug CONSOLE(QStringList const &lst = QStringList()) {
         m_debugMsg = lst;
         return QDebug(QtMsgType::QtInfoMsg);