sioctl_setval
int sioctl_setval(struct sioctl_hdl *, unsigned int, unsigned int);
sioctl_setval(hdl, c->addr, v);
sioctl_setval(hdl, i->ctladdr, val);
if (!sioctl_setval(d->sioctl.hdl, c->u.hw.addr, c->curval)) {