iio: adc: mp2629: fix wrong comparison of channel

Input voltage channel enum is compared against iio address instead
of the channel.

Fixes: 7abd9fb ("iio: adc: mp2629: Add support for mp2629 ADC driver")
Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20221029093000.45451-2-sravanhome@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: ssekar15

drivers/iio/adc/mp2629_adc.c

@@ -74,7 +74,7 @@ static int mp2629_read_raw(struct iio_dev *indio_dev,
 		if (ret)
 			return ret;
 
-		if (chan->address == MP2629_INPUT_VOLT)
+		if (chan->channel == MP2629_INPUT_VOLT)
 			rval &= GENMASK(6, 0);
 		*val = rval;
 		return IIO_VAL_INT;