sctp: check assoc before SCTP_ADDR_{MADE_PRIM, ADDED} event

Make sure SCTP_ADDR_{MADE_PRIM,ADDED} are sent only for associations
that have been established.

These events are described in rfc6458#section-6.1
SCTP_PEER_ADDR_CHANGE:
This tag indicates that an address that is
part of an existing association has experienced a change of
state (e.g., a failure or return to service of the reachability
of an endpoint via a specific transport address).

Signed-off-by: Jonas Falkevik <[e-mail]>
Acked-by: Marcelo Ricardo Leitner <[e-mail]>
Reviewed-by: Xin Long <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/sctp/ulpevent.c

···
 	struct sockaddr_storage addr;
 	struct sctp_ulpevent *event;
 
+	if (asoc->state < SCTP_STATE_ESTABLISHED)
+		return;
+
 	memset(&addr, 0, sizeof(struct sockaddr_storage));
 	memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);