mptcp: drop unused skb in subflow_token_join_request

This patch drops the unused parameter skb in subflow_token_join_request.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>

net/mptcp/subflow.c

@@ -64,8 +64,7 @@ static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk)
 }
 
 /* validate received token and create truncated hmac and nonce for SYN-ACK */
-static struct mptcp_sock *subflow_token_join_request(struct request_sock *req,
- const struct sk_buff *skb)
+static struct mptcp_sock *subflow_token_join_request(struct request_sock *req)
 {
  struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
  u8 hmac[SHA256_DIGEST_SIZE];
@@ -181,7 +180,7 @@ static int subflow_init_req(struct request_sock *req,
  subflow_req->remote_id = mp_opt.join_id;
  subflow_req->token = mp_opt.token;
  subflow_req->remote_nonce = mp_opt.nonce;
- subflow_req->msk = subflow_token_join_request(req, skb);
+ subflow_req->msk = subflow_token_join_request(req);
 
  /* Can't fall back to TCP in this case. */
  if (!subflow_req->msk)