Changed the order of processing SHUTDOWN ACK and COOKIE ACK
refer to section 8.4:Handle "Out of the Blue" Packets.

SHUTDOWN ACK chunk should be processed before processing
"Stale Cookie" ERROR or a COOKIE ACK.
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>