Function iio_device_reg_write 

pub unsafe extern "C" fn iio_device_reg_write(
    dev: *mut iio_device,
    address: u32,
    value: u32,
) -> c_int

@brief Set the value of a hardware register @param dev A pointer to an iio_device structure @param address The address of the register @param value The value to set the register to @return On success, 0 is returned @return On error, a negative errno code is returned