CppTools: Do not append '/' to fallback header paths

...since this will confuse the completer.

Task-number: QTCREATORBUG-13567
Change-Id: I4172d433f23f3907690d4c00f92fadb68fa354e8
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/cpptools/cppmodelmanager.cpp

@@ -393,8 +393,7 @@ ProjectPart::HeaderPaths CppModelManager::internalHeaderPaths() const
         const ProjectInfo pinfo = it.value();
         foreach (const ProjectPart::Ptr &part, pinfo.projectParts()) {
             foreach (const ProjectPart::HeaderPath &path, part->headerPaths) {
-                const ProjectPart::HeaderPath hp(CppSourceProcessor::cleanPath(path.path),
-                                                 path.type);
+                const ProjectPart::HeaderPath hp(QDir::cleanPath(path.path), path.type);
                 if (!headerPaths.contains(hp))
                     headerPaths += hp;
             }