GenericProject: Simplify Guard handling

GenericBuildSystem::refresh(...) already takes care of a guard,
so there is no need to get and store another one in
GenericBuildSystem::triggerParsing().

Change-Id: I83875ac4a42bfaf67997b5f1977f63913fc1d76c
Reviewed-by: hjk <hjk@qt.io>

src/plugins/genericprojectmanager/genericproject.cpp

@@ -173,8 +173,6 @@ private:
     CppTools::CppProjectUpdaterInterface *m_cppCodeModelUpdater = nullptr;
 
     Utils::FileSystemWatcher m_deployFileWatcher;
-
-    ParseGuard m_guard;
 };
 
 
@@ -263,7 +261,6 @@ GenericBuildSystem::~GenericBuildSystem()
 
 void GenericBuildSystem::triggerParsing()
 {
-    m_guard = guardParsingRun();
     refresh(Everything);
 }