stp: Discard any ASP-UP retransmissions

In some cases, there's some time between accepting the SCTP connection
and the execution of f_M3UA_CLNT_asp_up().  This may cause the
client sending re-transmitted ASP-UP messages.  Let's simply flush
and ignore those, rather than failing the test case.

Change-Id: Iea39e9543535977a3004b150e222ce8c7f4d821a
1 file changed