DCCP is going away soon, and had no twsk_unique() method.

We can directly call tcp_twsk_unique() for TCP sockets.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240507164140.940547-1-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>