CppTools: Tests: Fix memory leak

Detected by leak detector of Address Sanitizer.

Change-Id: I2aae2ba6fa2f218c9754d912dce7c398b1b384cb
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/cpptools/cpppointerdeclarationformatter_test.cpp

@@ -108,7 +108,8 @@ public:
         QVERIFY(ast);
 
         // Open file
-        TextEditor::BaseTextEditor *editor = TextEditor::PlainTextEditorFactory::createPlainTextEditor();
+        QScopedPointer<TextEditor::BaseTextEditor> editor(
+                    TextEditor::PlainTextEditorFactory::createPlainTextEditor());
         QString error;
         editor->open(&error, document->fileName(), document->fileName());
         QVERIFY(error.isEmpty());