Utils: Use override consistently

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

Change-Id: I89d27f359b6ee507153cb3712f61f81471ff0858
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/libs/utils/basetreeview.h

@@ -54,7 +54,7 @@ public:
     };
 
     BaseTreeView(QWidget *parent = 0);
-    ~BaseTreeView();
+    ~BaseTreeView() override;
 
     void setSettings(QSettings *settings, const QByteArray &key);