old_total_warn_count is not used

and was removed from THD

sql/sql_class.h

@@ -564,7 +564,7 @@ public:
   List<TABLE> temporary_tables_should_be_free; // list of temporary tables
   List	     <MYSQL_ERROR> warn_list;  
   uint	     warn_count[(uint) MYSQL_ERROR::WARN_LEVEL_END];
-  uint	     total_warn_count, old_total_warn_count;
+  uint	     total_warn_count;
   ulong	     query_id, warn_id, version, options, thread_id, col_access;
   ulong      current_stmt_id;
   ulong	     rand_saved_seed1, rand_saved_seed2;

sql/sql_parse.cc

@@ -1704,11 +1704,6 @@ mysql_execute_command(THD *thd)
   */
   if (tables || &lex->select_lex != lex->all_selects_list)
     mysql_reset_errors(thd);
-  /*
-    Save old warning count to be able to send to client how many warnings we
-    got
-  */
-  thd->old_total_warn_count= thd->total_warn_count;
 
 #ifdef HAVE_REPLICATION
   if (thd->slave_thread)