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

Change-Id: Ieb6df864ab82f77b2bee9e83aa0bfa2005715950
Refs: #3857
diff --git a/src/security/transform/hmac-filter.hpp b/src/security/transform/hmac-filter.hpp
index 5409952..0cec1fd 100644
--- a/src/security/transform/hmac-filter.hpp
+++ b/src/security/transform/hmac-filter.hpp
@@ -48,13 +48,13 @@
    *
    * @return The number of bytes that are actually accepted
    */
-  virtual size_t
+  size_t
   convert(const uint8_t* buf, size_t size) final;
 
   /**
    * @brief Finalize HMAC calculation and write the HMAC into next module.
    */
-  virtual void
+  void
   finalize() final;
 
 private: