msc: add and fix Iu mt call

Change-Id: I3ce29f3d9254656dc295674e8cec72a741b7764a
diff --git a/msc/MSC_Tests.ttcn b/msc/MSC_Tests.ttcn
index b4db43d..4ef592f 100644
--- a/msc/MSC_Tests.ttcn
+++ b/msc/MSC_Tests.ttcn
@@ -1658,7 +1658,7 @@
 }
 
 /* LU followed by MT call (including paging) */
-private function f_tc_lu_and_mt_call(charstring id, BSC_ConnHdlrPars pars) runs on BSC_ConnHdlr {
+friend function f_tc_lu_and_mt_call(charstring id, BSC_ConnHdlrPars pars) runs on BSC_ConnHdlr {
 	f_init_handler(pars);
 	var CallParameters cpars := valueof(t_CallParams('12345'H, 0));
 	cpars.use_osmux := pars.use_osmux;