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-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index e7851e3..09bbe57 100644
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -499,7 +499,7 @@
 	struct rs5c372 *rs5c372;
 	struct rtc_time tm;
 
-	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;