If changename notifier returns an error code, it gets incorrectly
cleared during rollback so the error is never returned to the user.
Found while testing similar code for MTU changes.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
                strlcpy(dev->name, newname, IFNAMSIZ);
 
 rollback:
-       err = device_rename(&dev->dev, dev->name);
-       if (err) {
+       ret = device_rename(&dev->dev, dev->name);
+       if (ret) {
                memcpy(dev->name, oldname, IFNAMSIZ);
-               return err;
+               return ret;
        }
 
        write_lock_bh(&dev_base_lock);