Send also a packet containing an ABORT chunk in response to an OOTB packet

containing a COOKIE-ECHO chunk.

MFC after: 3 days

sys/netinet/sctputil.c

@@ -4047,9 +4047,6 @@ sctp_handle_ootb(struct mbuf *m, int iphlen, int offset,
 		case SCTP_INIT:
 			contains_init_chunk = 1;
 			break;
-		case SCTP_COOKIE_ECHO:
-			/* We hit here only if the assoc is being freed */
-			return;
 		case SCTP_PACKET_DROPPED:
 			/* we don't respond to pkt-dropped */
 			return;