iio: adc: ad7124: fix division by zero in ad7124_set_channel_odr()

iio: adc: ad7124: fix division by zero in ad7124_set_channel_odr()

In the ad7124_write_raw() function, parameter val can potentially
be zero. This may lead to a division by zero when DIV_ROUND_CLOSEST()
is called within ad7124_set_channel_odr(). The ad7124_write_raw()
function is invoked through the sequence: iio_write_channel_raw() ->
iio_write_channel_attribute() -> iio_channel_write(), with no checks
in place to ensure val is non-zero.

Cc: stable@vger.kernel.org
Fixes: 7b8d045e497a ("iio: adc: ad7124: allow more than 8 channels")
Signed-off-by: Zicheng Qu <quzicheng@huawei.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20241022134330.574601-1-quzicheng@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>