iio: adc: at91-sama5d2_adc: move oversampling storage in its function

Move the storage of oversampling_ratio in at91_adc_config_emr().
This prepares for the next commits.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-13-claudiu.beznea@microchip.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/at91-sama5d2_adc.c

@@ -793,6 +793,8 @@ static int at91_adc_config_emr(struct at91_adc_state *st,
 
 	at91_adc_writel(st, EMR, emr);
 
+	st->oversampling_ratio = oversampling_ratio;
+
 	return 0;
 }
 
@@ -1705,8 +1707,6 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
 		mutex_lock(&st->lock);
 		/* update ratio */
 		ret = at91_adc_config_emr(st, val);
-		if (!ret)
-			st->oversampling_ratio = val;
 		mutex_unlock(&st->lock);
 		iio_device_release_direct_mode(indio_dev);
 		return ret;