iwi_free_tx_ring
static void iwi_free_tx_ring(struct iwi_softc *, struct iwi_tx_ring *);
iwi_free_tx_ring(sc, &sc->txq[0]);
iwi_free_tx_ring(sc, &sc->txq[1]);
iwi_free_tx_ring(sc, &sc->txq[2]);
iwi_free_tx_ring(sc, &sc->txq[3]);
fail: iwi_free_tx_ring(sc, ring);