i2c: Stop using i2c_adapter.class_dev

Stop using i2c_adapter.class_dev, as it is going to be removed
soon. Luckily, there are only 4 RTC drivers affected.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
diff --git a/drivers/rtc/rtc-ds1672.c b/drivers/rtc/rtc-ds1672.c
index 205fa28..dfef163 100644
--- a/drivers/rtc/rtc-ds1672.c
+++ b/drivers/rtc/rtc-ds1672.c
@@ -199,7 +199,7 @@
 	struct i2c_client *client;
 	struct rtc_device *rtc;
 
-	dev_dbg(adapter->class_dev.dev, "%s\n", __FUNCTION__);
+	dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
 		err = -ENODEV;