Use simpler Plugin::initialize() when feasible

Change-Id: I567965d266f20526bda9f823e31a04b354d53fb1
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/cmakeprojectmanager/cmakeprojectplugin.h

@@ -36,7 +36,7 @@ private slots:
 #endif
 
 private:
-    bool initialize(const QStringList &arguments, QString *errorMessage) final;
+    void initialize() final;
     void extensionsInitialized() final;
 
     void updateContextActions(ProjectExplorer::Node *node);