sctp: Clear fast_recovery on the transport when T3 timer expires.

If T3 timer expires, we are retransmitting data due to timeout any
any fast recovery is null and void.  We can clear the fast recovery
flag.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>

net/sctp/transport.c

@@ -503,6 +503,9 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 		transport->ssthresh = max(transport->cwnd/2,
 					  4*transport->asoc->pathmtu);
 		transport->cwnd = transport->asoc->pathmtu;
+
+		/* T3-rtx also clears fast recovery on the transport */
+		transport->fast_recovery = 0;
 		break;
 
 	case SCTP_LOWER_CWND_FAST_RTX: