sctp: add the missing setting for asoc encap_port

This patch is to add the missing setting back for asoc encap_port.

Fixes: 8dba2960 ("sctp: add SCTP_REMOTE_UDP_ENCAPS_PORT sockopt")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/socket.c

@@ -4473,6 +4473,7 @@ static int sctp_setsockopt_encap_port(struct sock *sk,
 				    transports)
 			t->encap_port = encap_port;
 
+		asoc->encap_port = encap_port;
 		return 0;
 	}