_ath_getbuf_locked
bf = _ath_getbuf_locked(sc, btype);
bf = _ath_getbuf_locked(sc, ATH_BUFTYPE_NORMAL);
extern struct ath_buf * _ath_getbuf_locked(struct ath_softc *sc,
bf = _ath_getbuf_locked(sc, ATH_BUFTYPE_NORMAL);