tcp: avoid dst->ops->check() call in tcp_v{4,6}_do_rcv()

tcp: avoid dst->ops->check() call in tcp_v{4,6}_do_rcv()

If incoming skb dst matches the socket cached one,
there is no need to call again dst->ops->check().

Network layer already validated the skb dst for us,
usually from tcp_v{4,6}_early_demux().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260306154322.1086539-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>