net_sched: add back BH safety to tcf_lock

Jamal reported that we had to use BH safety after all,
because stats can be updated from BH handler.

Fixes: 3133d5c1 ("net_sched: remove BH blocking in eight actions")
Fixes: 53df77e7 ("net_sched: act_skbmod: use RCU in tcf_skbmod_dump()")
Fixes: e97ae742 ("net_sched: act_tunnel_key: use RCU in tunnel_key_dump()")
Fixes: 48b5e5db ("net_sched: act_vlan: use RCU in tcf_vlan_dump()")
Reported-by: Jamal Hadi Salim <jhs@mojatatu.com>
Closes: https://lore.kernel.org/netdev/CAM0EoMmhq66EtVqDEuNik8MVFZqkgxFbMu=fJtbNoYD7YXg4bA@mail.gmail.com/


Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20250901092608.2032473-1-edumazet@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>