explicit --sleep is removed in favor of wait_for_slave_io_to_stop.inc.
The status reporting uses `SHOW SLAVE STATUS' *not* possibly buggy "SHOW STATUS LIKE 'Slave_running'".


mysql-test/r/rpl_packet.result:
  Recording the necessary Slave_IO_Running status at the end of the bug test.
  It must be No.
mysql-test/t/rpl_packet.test:
  Removing sleep; wait_for_slave_io_to_stop.inc instead;
  Original "SHOW STATUS LIKE 'Slave_running'" seems to be buggy (to be reported) as with the macro above
  there were evidence slave IO was stopped indeed but "SHOW STATUS" did not find that (see failures in pb)