iio: addac: ad74413r: fix off by one in ad74413r_parse_channel_config()

The > needs to be >= to prevent accessing one element beyond the end of
the st->channel_configs[] array.

Fixes: fea251b6a5 ("iio: addac: add AD74413R driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/addac/ad74413r.c

@@ -1150,7 +1150,7 @@ static int ad74413r_parse_channel_config(struct iio_dev *indio_dev,
 		return ret;
 	}
 
-	if (index > AD74413R_CHANNEL_MAX) {
+	if (index >= AD74413R_CHANNEL_MAX) {
 		dev_err(st->dev, "Channel index %u is too large\n", index);
 		return -EINVAL;
 	}