sctp: Correctly start rtx timer on new packet transmissions.

Commit 62aeaff5
(sctp: Start T3-RTX timer when fast retransmitting lowest TSN)
introduced a regression where it was possible to forcibly
restart the sctp retransmit timer at the transmission of any
new chunk.  This resulted in much longer timeout times and
sometimes hung sctp connections.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/outqueue.c

@@ -929,7 +929,6 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
 		}
 
 		/* Finally, transmit new packets.  */
-		start_timer = 0;
 		while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
 			/* RFC 2960 6.5 Every DATA chunk MUST carry a valid
 			 * stream identifier.
@@ -1028,7 +1027,7 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
 			list_add_tail(&chunk->transmitted_list,
 				      &transport->transmitted);
 
-			sctp_transport_reset_timers(transport, start_timer-1);
+			sctp_transport_reset_timers(transport, 0);
 
 			q->empty = 0;