ping: Code refactoring

Change-Id: I8b4e2c9dd3ba3adfae8d296a5635b048b35cf593
Refs: #3137
diff --git a/tools/ping/client/tracer.hpp b/tools/ping/client/tracer.hpp
index 5a8cd35..f62b9b8 100644
--- a/tools/ping/client/tracer.hpp
+++ b/tools/ping/client/tracer.hpp
@@ -43,7 +43,8 @@
   Tracer(Ping& ping, const Options& options);
 
   /**
-   * Prints ping results when response received
+   * @brief Prints ping results when response received
+   *
    * @param seq ping sequence number
    * @param rtt round trip time
    */
@@ -51,14 +52,15 @@
   onResponse(uint64_t seq, Rtt rtt);
 
   /**
-   * Prints ping results when timed out
+   * @brief Prints ping results when timed out
+   *
    * @param seq ping sequence number
    */
   void
   onTimeout(uint64_t seq);
 
   /**
-   * Outputs ping errors to cerr
+   * @brief Outputs ping errors to cerr
    */
   void
   onError(std::string msg);