CppTools: Call ProjectInfo::finish when we get it

No need to require the project managers to do this. Also, it is easy to
forget.

Change-Id: I96f7a5e5547418678af9653e5753c372f0880e5a
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/autotoolsprojectmanager/autotoolsproject.cpp

@@ -305,6 +305,5 @@ void AutotoolsProject::updateCppCodeModel()
     foreach (Core::Id language, languages)
         setProjectLanguage(language, true);
 
-    pInfo.finish();
     m_codeModelFuture = modelManager->updateProjectInfo(pInfo);
 }