for_each_kring_n
for_each_kring_n(_i, _k, (_na)->tx_rings, (_na)->num_tx_rings)
for_each_kring_n(_i, _k, (_na)->tx_rings, (_na)->num_tx_rings + 1)
for_each_kring_n(_i, _k, (_na)->rx_rings, (_na)->num_rx_rings)
for_each_kring_n(_i, _k, (_na)->rx_rings, (_na)->num_rx_rings + 1)