net: rps: remove kfree_rcu_mightsleep() use

Add an rcu_head to sd_flow_limit and rps_sock_flow_table structs
to use the more conventional and predictable k[v]free_rcu().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250407163602.170356-5-edumazet@google.com


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