iio:gyro: adis16136: divide by zero in write_frequency()

It's slightly cleaner to use kstrtouint() because we pass unsigned ints
to adis16136_set_freq().  On 64 bit systems, if the user passed LONG_MIN
then it we would get past the test against zero but crash in
adis16136_set_freq() because we truncate the high bits away.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-By: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/gyro/adis16136.c

@@ -203,10 +203,10 @@ static ssize_t adis16136_write_frequency(struct device *dev,
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct adis16136 *adis16136 = iio_priv(indio_dev);
-	long val;
+	unsigned int val;
 	int ret;
 
-	ret = kstrtol(buf, 10, &val);
+	ret = kstrtouint(buf, 10, &val);
 	if (ret)
 		return ret;