sctp: Fix to start T5-shutdown-guard timer while enter SHUTDOWN-SENT state

RFC 4960: Section 9.2
The sender of the SHUTDOWN MAY also start an overall guard timer
'T5-shutdown-guard' to bound the overall time for the shutdown
sequence.  At the expiration of this timer, the sender SHOULD abort
the association by sending an ABORT chunk.  If the 'T5-shutdown-
guard' timer is used, it SHOULD be set to the recommended value of 5
times 'RTO.Max'.

The timer 'T5-shutdown-guard' is used to counter the overall time
for shutdown sequence, and it's start by the sender of the SHUTDOWN.
So timer 'T5-shutdown-guard' should be start when we send the first
SHUTDOWN chunk and enter the SHUTDOWN-SENT state, not start when we
receipt of the SHUTDOWN primitive and enter SHUTDOWN-PENDING state.

If 'T5-shutdown-guard' timer is start at SHUTDOWN-PENDING state, the
association may be ABORT while data is still transmitting.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c
index d991237..dd4ddc4 100644
--- a/net/sctp/sm_statetable.c
+++ b/net/sctp/sm_statetable.c
@@ -897,7 +897,7 @@
 	/* SCTP_STATE_ESTABLISHED */ \
 	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
 	/* SCTP_STATE_SHUTDOWN_PENDING */ \
-	TYPE_SCTP_FUNC(sctp_sf_t5_timer_expire), \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
 	/* SCTP_STATE_SHUTDOWN_SENT */ \
 	TYPE_SCTP_FUNC(sctp_sf_t5_timer_expire), \
 	/* SCTP_STATE_SHUTDOWN_RECEIVED */ \