net: fib_rules: annotate data-races around rule->[io]ifindex

net: fib_rules: annotate data-races around rule->[io]ifindex

rule->iifindex and rule->oifindex can be read without holding RTNL.

Add READ_ONCE()/WRITE_ONCE() annotations where needed.

Fixes: 32affa5578f0 ("fib: rules: no longer hold RTNL in fib_nl_dumprule()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250206083051.2494877-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>