iio:chemical:bme680: Fix, report temperature in millidegrees

The standard unit for temperature is millidegrees Celcius. Adapt the
driver to report in millidegrees instead of degrees.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Fixes: 1b3bd859 ("iio: chemical: Add support for Bosch BME680 sensor");
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/chemical/bme680_core.c

@@ -583,8 +583,7 @@ static int bme680_gas_config(struct bme680_data *data)
 	return ret;
 }
 
-static int bme680_read_temp(struct bme680_data *data,
-			    int *val, int *val2)
+static int bme680_read_temp(struct bme680_data *data, int *val)
 {
 	struct device *dev = regmap_get_device(data->regmap);
 	int ret;
@@ -617,10 +616,9 @@ static int bme680_read_temp(struct bme680_data *data,
 	 * compensate_press/compensate_humid to get compensated
 	 * pressure/humidity readings.
 	 */
-	if (val && val2) {
-		*val = comp_temp;
-		*val2 = 100;
-		return IIO_VAL_FRACTIONAL;
+	if (val) {
+		*val = comp_temp * 10; /* Centidegrees to millidegrees */
+		return IIO_VAL_INT;
 	}
 
 	return ret;
@@ -635,7 +633,7 @@ static int bme680_read_press(struct bme680_data *data,
 	s32 adc_press;
 
 	/* Read and compensate temperature to get a reading of t_fine */
-	ret = bme680_read_temp(data, NULL, NULL);
+	ret = bme680_read_temp(data, NULL);
 	if (ret < 0)
 		return ret;
 
@@ -668,7 +666,7 @@ static int bme680_read_humid(struct bme680_data *data,
 	u32 comp_humidity;
 
 	/* Read and compensate temperature to get a reading of t_fine */
-	ret = bme680_read_temp(data, NULL, NULL);
+	ret = bme680_read_temp(data, NULL);
 	if (ret < 0)
 		return ret;
 
@@ -761,7 +759,7 @@ static int bme680_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_PROCESSED:
 		switch (chan->type) {
 		case IIO_TEMP:
-			return bme680_read_temp(data, val, val2);
+			return bme680_read_temp(data, val);
 		case IIO_PRESSURE:
 			return bme680_read_press(data, val, val2);
 		case IIO_HUMIDITYRELATIVE: