inet: cache listen_sock_qlen() and read rskq_defer_accept once

Cache listen_sock_qlen() to limit false sharing, and read
rskq_defer_accept once as it might change under us.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed