uhci_alloc_std_chain
usbd_status uhci_alloc_std_chain(struct uhci_softc *, u_int,
err = uhci_alloc_std_chain(sc, len, xfer, &data, &dataend);
err = uhci_alloc_std_chain(sc, xfer->length, xfer, &data, &dataend);
err = uhci_alloc_std_chain(sc, len, xfer, &data, &dataend);
uhci_alloc_std_chain(sc, xfer->length, xfer, &data, &dataend);