watchdog: Use put_device on error

We should use put_device() instead of freeing device
directly after device_initialize().

Fixes: cb36e29b ("watchdog: initialize device before misc_register")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200824031230.31050-1-dinghao.liu@zju.edu.cnSigned-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/watchdog_dev.c

@@ -1023,7 +1023,7 @@ static int watchdog_cdev_register(struct watchdog_device *wdd)
 				pr_err("%s: a legacy watchdog module is probably present.\n",
 					wdd->info->identity);
 			old_wd_data = NULL;
-			kfree(wd_data);
+			put_device(&wd_data->dev);
 			return err;
 		}
 	}