CVE-2025-39925 can: j1939: implement NETDEV_UNREGISTER notification handler

In the Linux kernel, the following vulnerability has been resolved: can: j1939: implement NETDEVUNREGISTER notification handler syzbot is reporting unregisternetdevice: waiting for vcan0 to become free. Usage count = 2 problem, for j1939 protocol did not have NETDEVUNREGISTER notification handler...