MDEV-7999 - PROFILING routines take 0.2% when profiling disabled

This is an addition to original patch. Embedded server does extra calls of
PROFILING::start_new_query() and PROFILING::finish_current_query(), which
cause DBUG_ASSERT(!current) failure.

Removed these extra calls: dispatch_command() does all needed job.

libmysqld/lib_sql.cc

@@ -130,10 +130,6 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
     thd= (THD *) mysql->thd;
   }
 
-#if defined(ENABLED_PROFILING)
-  thd->profiling.start_new_query();
-#endif
-
   thd->clear_data_list();
   /* Check that we are calling the client functions in right order */
   if (mysql->status != MYSQL_STATUS_READY)
@@ -178,10 +174,6 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
 
   thd->mysys_var= 0;
 
-#if defined(ENABLED_PROFILING)
-  thd->profiling.finish_current_query();
-#endif
-
 end:
   thd->reset_globals();
   return result;