sctp: Fix the SNMP counter of SCTP_MIB_OUTOFBLUES

RFC3873 defined SCTP_MIB_OUTOFBLUES:

 sctpOutOfBlues OBJECT-TYPE
   SYNTAX         Counter32
   MAX-ACCESS     read-only
   STATUS         current
   DESCRIPTION
        "The number of out of the blue packets received by the host.
        An out of the blue packet is an SCTP packet correctly formed,
        including the proper checksum, but for which the receiver was
        unable to identify an appropriate association."
   REFERENCE
        "Section 8.4 in RFC2960 deals with the Out-Of-The-Blue
         (OOTB) packet definition and procedures."

But OOTB packet INIT, INIT-ACK and SHUTDOWN-ACK(COOKIE-WAIT or
COOKIE-ECHOED state) are not counted by SCTP_MIB_OUTOFBLUES.

Case 1(INIT):

Endpoint A               Endpoint B
(CLOSED)                 (CLOSED)

 INIT     ---------->
          <----------    ABORT

Case 2(INIT-ACK):

Endpoint A               Endpoint B
(CLOSED)                 (CLOSED)

 INIT-ACK  ---------->
           <----------   ABORT

Case 3(SHUTDOWN-ACK):

Endpoint A               Endpoint B
(CLOSED)                 (CLOSED)

          <----------    INIT
 SHUTDOWN-ACK  ---------->
           <----------   SHUTDOWN-COMPLETE

Case 4(SHUTDOWN-ACK):

Endpoint A               Endpoint B
(CLOSED)                 (COOKIE-ECHOED)

 SHUTDOWN-ACK  ---------->
           <----------   SHUTDOWN-COMPLETE

This patch fixed the problem.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>