hwmon: (ds1621) Update zbits after conversion rate change

commit 39c627a0 upstream.

After the conversion rate is changed, the zbits are not updated,
but should be, since they are used later in the set_temp function.

Fixes: a50d9a4d ("hwmon: (ds1621) Fix temperature rounding operations")
Reported-by: Murat Ilsever <murat.ilsever@gmail.com>
Signed-off-by: Robert Coulson <rob.coulson@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

drivers/hwmon/ds1621.c

@@ -311,6 +311,7 @@ static ssize_t set_convrate(struct device *dev, struct device_attribute *da,
 	data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT);
 	i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf);
 	data->update_interval = ds1721_convrates[resol];
+	data->zbits = 7 - resol;
 	mutex_unlock(&data->update_lock);
 
 	return count;