ieee802154: Restore initial state on failed device_rename() in cfg802154_switch_netns()

ieee802154: Restore initial state on failed device_rename() in cfg802154_switch_netns()

Currently, the return value of device_rename() is not acted upon.

To avoid an inconsistent state in case of failure, roll back the changes
made before the device_rename() call.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 66e5c2672cd1 ("ieee802154: add netns support")
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Ivan Abramov <i.abramov@mt-integration.ru>
Link: https://lore.kernel.org/20250403101935.991385-2-i.abramov@mt-integration.ru
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>