* @tx_slot: slot holding transmitted message, slot is taken from
* canque_test_outslot() call and is freed by canque_free_outslot()
* or rescheduled canque_again_outslot()
* @tx_slot: slot holding transmitted message, slot is taken from
* canque_test_outslot() call and is freed by canque_free_outslot()
* or rescheduled canque_again_outslot()