src: drop 'virtual' from functions marked 'final' or 'override'

Change-Id: Ieb6df864ab82f77b2bee9e83aa0bfa2005715950
Refs: #3857
diff --git a/src/util/indented-stream.hpp b/src/util/indented-stream.hpp
index 31e5839..32b60e8 100644
--- a/src/util/indented-stream.hpp
+++ b/src/util/indented-stream.hpp
@@ -56,7 +56,6 @@
 public:
   IndentedStream(std::ostream& os, const std::string& indent);
 
-  virtual
   ~IndentedStream() override;
 
 private:
@@ -66,7 +65,7 @@
   public:
     StreamBuf(std::ostream& os, const std::string& indent);
 
-    virtual int
+    int
     sync() override;
 
   private: