rtc: isl1208: switch to rtc_register_device

Fix possible race condition.
It is not allowed to return with an error code after RTC is registered.
Suggested-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NDenis Osterland <Denis.Osterland@diehl.com>
Reviewed-by: NMichael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-isl1208.c

@@ -635,12 +635,12 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	if (isl1208_i2c_validate_client(client) < 0)
 		return -ENODEV;
 
-	rtc = devm_rtc_device_register(&client->dev, isl1208_driver.driver.name,
-				  &isl1208_rtc_ops,
-				  THIS_MODULE);
+	rtc = devm_rtc_allocate_device(&client->dev);
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);
 
+	rtc->ops = &isl1208_rtc_ops;
+
 	i2c_set_clientdata(client, rtc);
 
 	rc = isl1208_i2c_get_sr(client);
@@ -674,7 +674,7 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		}
 	}
 
-	return 0;
+	return rtc_register_device(rtc);
 }
 
 static int