bsc-sccplite: Fix expected DLCX in HO tests

* TTCN3 code was not ACKing the DLCXs, and as a result retransmitted
DLCX BSC->MGW were being counted as 2nd DLCX.

* In SCCPLite, only 1 DLCX is expected BSC->MGW, because the BSC only
takes care of the BTS-side conn in the endpoint, while MSC takes care of
the MSC-side conn (which is not sent in this case because doesn't really
involved the BSC other than forwarding the message, which will already
be tested in other places in forthcoming commits).

* Getting rid of retransmissions by ACKing the DLCX, it unconvers a bug
in TC_ho_out_fail_no_ho_detect when on AoIP, where BSC only deletes one
of the 2 previously created connections.

* Code is refactored into the function because its logic is made more
complex, and may be even more complex in forthcoming commits when we add
MGCP-over-IPA forwarding verification support.

Change-Id: Ia1d0db9af073760105cc8509e228e317dbea2268
1 file changed