zd_usb_iowrite16v_async
r = zd_usb_iowrite16v_async(&chip->usb, ioreqs16, count16);
r = zd_usb_iowrite16v_async(&chip->usb, &ioreqs[i], j);
r = zd_usb_iowrite16v_async(usb, ioreqs, count);
int zd_usb_iowrite16v_async(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,