RNDGETSRCNUM
ret = (fp->f_ops->fo_ioctl)(fp, RNDGETSRCNUM, &rstbuf);
ret = (fp->f_ops->fo_ioctl)(fp, RNDGETSRCNUM, &rstbuf);
case RNDGETSRCNUM:
case RNDGETSRCNUM: { /* Get entropy sources by number. */