msc: rather not use decmatch in f_tc_ho_inter_msc_out()

TC_ho_inter_msc_out fails on jenkins in a way that i cannot reproduce. A
possible source is the decmatch for the Handover Request message. The
jenkins logs show:

MSC_Tests.ttcn:6005 Warning: Decoded content matching failed, because the buffer was not empty after decoding. Remaining octets: 22.

Change-Id: I20b5594c7e083af791525231f24d3ed089c18910
diff --git a/msc/MSC_Tests.ttcn b/msc/MSC_Tests.ttcn
index 5c63b63..e548c5c 100644
--- a/msc/MSC_Tests.ttcn
+++ b/msc/MSC_Tests.ttcn
@@ -6005,7 +6005,7 @@
 	alt {
 	[] GSUP.receive(tr_GSUP_E_AN_APDU(OSMO_GSUP_MSGT_E_PREPARE_HANDOVER_REQUEST,
 				pars.imsi, destination_name := remote_msc_name,
-				an_apdu := t_GSUP_AN_APDU(OSMO_GSUP_AN_PROTO_48006, decmatch expect_ho_request))) -> value prep_ho_req;
+				an_apdu := t_GSUP_AN_APDU(OSMO_GSUP_AN_PROTO_48006, pdu := ?))) -> value prep_ho_req;
 	[] GSUP.receive(tr_GSUP_E_AN_APDU(OSMO_GSUP_MSGT_E_PREPARE_HANDOVER_REQUEST)) {
 		setverdict(fail, "Wrong OSMO_GSUP_MSGT_E_PREPARE_HANDOVER_REQUEST message received");
 		mtc.stop;
@@ -6016,10 +6016,14 @@
 	f_gsup_find_ie(prep_ho_req, OSMO_GSUP_SOURCE_NAME_IE, source_name_ie);
 	var octetstring local_msc_name := source_name_ie.source_name;
 
-	/* To forward the actual chosen encryption algorithm, decode the received PDU */
+	/* Decode PDU to 1) match with expect_ho_request and 2) to forward the actual chosen encryption algorithm. */
 	var GSUP_IeValue an_apdu_ie;
 	f_gsup_find_ie(prep_ho_req, OSMO_GSUP_AN_APDU_IE, an_apdu_ie);
 	ho_request := dec_PDU_BSSAP(an_apdu_ie.an_apdu.pdu);
+	if (not match(ho_request, expect_ho_request)) {
+		setverdict(fail, "Wrong PDU in OSMO_GSUP_MSGT_E_PREPARE_HANDOVER_REQUEST message received");
+		mtc.stop;
+	}
 
 	/* Remote MSC has figured out its BSC and signals success */
 	var PDU_ML3_NW_MS rr_ho_cmd := valueof(ts_RR_HandoverCommand);