iio: adc: ad7280a: fix ad7280_store_balance_timer()

Use correct argument to iio_str_to_fixpoint() to parse 3 decimal places.

iio_str_to_fixpoint() has a bit of an unintuitive API where the
fract_mult parameter is the multiplier of the first decimal place as if
it was already an integer.  So to get 3 decimal places, fract_mult must
be 100 rather than 1000.

Fixes: 96ccdbc ("staging:iio:adc:ad7280a: Standardize extended ABI naming")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: dlech

drivers/iio/adc/ad7280a.c

@@ -541,7 +541,7 @@ static ssize_t ad7280_store_balance_timer(struct iio_dev *indio_dev,
 	int val, val2;
 	int ret;
 
-	ret = iio_str_to_fixpoint(buf, 1000, &val, &val2);
+	ret = iio_str_to_fixpoint(buf, 100, &val, &val2);
 	if (ret)
 		return ret;