VcsManager: Register IVersionControls with VcsManager

Get some more objects out of the pool.

Change-Id: Id93021b712307c4777dc39b9d15aa18a46318885
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/clearcase/clearcaseplugin.cpp

@@ -410,7 +410,7 @@ bool ClearCasePlugin::initialize(const QStringList & /*arguments */, QString *er
 
     Context context(CLEARCASE_CONTEXT);
 
-    initializeVcs(new ClearCaseControl(this), context);
+    initializeVcs<ClearCaseControl>(context, this);
 
     m_clearcasePluginInstance = this;
     connect(ICore::instance(), &ICore::coreAboutToClose, this, &ClearCasePlugin::closing);