act_ife: move tcfa_lock down to where necessary

The only time we need to take tcfa_lock is when adding
a new metainfo to an existing ife->metalist. We don't need
to take tcfa_lock so early and so broadly in tcf_ife_init().

This means we can always take ife_mod_lock first, avoid the
reverse locking ordering warning as reported by Vlad.

Reported-by: Vlad Buslov <vladbu@mellanox.com>
Tested-by: Vlad Buslov <vladbu@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>