Replace static_casts by QOverload where possible

Mainly to get rid of the QProcess::finished deprecation warning.

Also adjust coding style in the surrounding connects when needed.

Change-Id: I12f9b248c7974b892c4a069356e578e80f8c59e9
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/qtsupport/qtversionmanager.cpp

@@ -138,7 +138,7 @@ void QtVersionManager::triggerQtVersionRestore()
     if (configFileName.exists()) {
         m_configFileWatcher = new FileSystemWatcher(m_instance);
         connect(m_configFileWatcher, &FileSystemWatcher::fileChanged,
-                m_fileWatcherTimer, static_cast<void (QTimer::*)()>(&QTimer::start));
+                m_fileWatcherTimer, QOverload<>::of(&QTimer::start));
         m_configFileWatcher->addFile(configFileName.toString(),
                                      FileSystemWatcher::WatchModifiedDate);
     } // exists