CppTools: Use override consistently

clang-tidy fixes from modernize-use-override check.

Change-Id: I0e6d6a9df3e87b8042ccc5ea0adc70070a3821d6
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/cpptools/baseeditordocumentparser.h

@@ -72,7 +72,7 @@ public:
 
 public:
     BaseEditorDocumentParser(const QString &filePath);
-    virtual ~BaseEditorDocumentParser();
+    ~BaseEditorDocumentParser() override;
 
     QString filePath() const;
     Configuration configuration() const;