hwmon: (emc6w201) Fix temperature limit range

Temperature limit range is [-127, 127], not [-127, 128].
The wrong range caused a bad limit to be written into the chip
if the limit was set to a value of 128 degrees C or above.

Also use DIV_ROUND_CLOSEST instead of a plain divide operation
to reduce the rounding error when writing temperature limits.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NJean Delvare <jdelvare@suse.de>

drivers/hwmon/emc6w201.c

@@ -252,12 +252,12 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 	if (err < 0)
 		return err;
 
-	val /= 1000;
+	val = DIV_ROUND_CLOSEST(val, 1000);
 	reg = (sf == min) ? EMC6W201_REG_TEMP_LOW(nr)
 			  : EMC6W201_REG_TEMP_HIGH(nr);
 
 	mutex_lock(&data->update_lock);
-	data->temp[sf][nr] = clamp_val(val, -127, 128);
+	data->temp[sf][nr] = clamp_val(val, -127, 127);
 	err = emc6w201_write8(client, reg, data->temp[sf][nr]);
 	mutex_unlock(&data->update_lock);