drivers/rtc: Replace PTR_RET with PTR_ERR_OR_ZERO

PTR_RET is now deprecated. Use PTR_ERR_OR_ZERO instead.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/rtc/rtc-isl12022.c b/drivers/rtc/rtc-isl12022.c
index 5dbdc44..03b8911 100644
--- a/drivers/rtc/rtc-isl12022.c
+++ b/drivers/rtc/rtc-isl12022.c
@@ -268,7 +268,7 @@
 	isl12022->rtc = devm_rtc_device_register(&client->dev,
 					isl12022_driver.driver.name,
 					&isl12022_rtc_ops, THIS_MODULE);
-	return PTR_RET(isl12022->rtc);
+	return PTR_ERR_OR_ZERO(isl12022->rtc);
 }
 
 static const struct i2c_device_id isl12022_id[] = {