CVE-2025-21970 net/mlx5: Bridge, fix the crash caused by LAG state check

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Bridge, fix the crash caused by LAG state check When removing LAG device from bridge, NETDEVCHANGEUPPER event is triggered. Driver finds the lower devices PFs to flush all the offloaded entries. And mlx5lagissharedfdb i...