iio: accel: bma400: prevent setting accel scale too low

This puts an upper bound on "val2" but it also needs to have a lower
bound (BMA400_SCALE_MIN).

Fixes: 465c811f ("iio: accel: Add driver for the BMA400")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/bma400_core.c

@@ -752,7 +752,8 @@ static int bma400_write_raw(struct iio_dev *indio_dev,
 		mutex_unlock(&data->mutex);
 		return ret;
 	case IIO_CHAN_INFO_SCALE:
-		if (val != 0 || val2 > BMA400_SCALE_MAX)
+		if (val != 0 ||
+		    val2 < BMA400_SCALE_MIN || val2 > BMA400_SCALE_MAX)
 			return -EINVAL;
 
 		mutex_lock(&data->mutex);