Fix clang compilation

Change-Id: Ic2617b5eca47ebbcc04119dd7e064b8f570fbc09
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/clangcodemodel/clangcompletion.cpp

@@ -175,7 +175,7 @@ static QList<CodeCompletionResult> unfilteredCompletion(const ClangCompletionAss
     }
 
     QList<CodeCompletionResult> result = wrapper->codeCompleteAt(line, column + 1, unsavedFiles);
-    Utils::sort(result);
+    ::Utils::sort(result);
 
     if (DebugTiming)
         qDebug() << "... Completion done in" << t.elapsed() << "ms, with" << result.count() << "items.";