Core: Use Qt5-style connects

The heavy lifting was done by clazy.

Change-Id: I2dde14919d917816d02117338205f8f861d8af0a
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/coreplugin/actionmanager/commandbutton.h

@@ -48,10 +48,9 @@ public:
     QString toolTipBase() const;
     void setToolTipBase(const QString &toolTipBase);
 
-private slots:
+private:
     void updateToolTip();
 
-private:
     QPointer<Command> m_command;
     QString m_toolTipBase;
 };