Merge branch 'sctp-bad-revert'

Xin Long says:

====================
sctp: fix the incorrect revert

commit a18e875b2f47 ("sctp: do asoc update earlier in
sctp_sf_do_dupcook_a") only keeps the SHUTDOWN and
COOKIE-ACK with the same asoc, not transport.

So instead of revert commit 55a1670c1c57 ("sctp: Fix bundling
of SHUTDOWN with COOKIE-ACK"), we should revert b53bcdd57ffe
("sctp: Fix SHUTDOWN CTSN Ack in the peer restart case").
====================

Signed-off-by: David S. Miller <davem@davemloft.net>