hwmon: (adt7470) Return proper error code for adt7470_probe()

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
index 9e77571..87d92a5 100644
--- a/drivers/hwmon/adt7470.c
+++ b/drivers/hwmon/adt7470.c
@@ -1286,8 +1286,10 @@
 	init_completion(&data->auto_update_stop);
 	data->auto_update = kthread_run(adt7470_update_thread, client,
 					dev_name(data->hwmon_dev));
-	if (IS_ERR(data->auto_update))
+	if (IS_ERR(data->auto_update)) {
+		err = PTR_ERR(data->auto_update);
 		goto exit_unregister;
+	}
 
 	return 0;