sctp: fix ignoring asoc_id for tcp-style sockets on SCTP_CONTEXT sockopt

A similar fix as Patch "sctp: fix ignoring asoc_id for tcp-style sockets on
SCTP_DEFAULT_SEND_PARAM sockopt" on SCTP_CONTEXT sockopt.

Fixes: 49b037ac ("sctp: use SCTP_FUTURE_ASSOC and add SCTP_CURRENT_ASSOC for SCTP_CONTEXT sockopt")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/socket.c

@@ -3540,6 +3540,9 @@ static int sctp_setsockopt_context(struct sock *sk, char __user *optval,
 		return 0;
 	}
 
+	if (sctp_style(sk, TCP))
+		params.assoc_id = SCTP_FUTURE_ASSOC;
+
 	if (params.assoc_id == SCTP_FUTURE_ASSOC ||
 	    params.assoc_id == SCTP_ALL_ASSOC)
 		sp->default_rcv_context = params.assoc_value;