bsc: Rename s/use_osmux/use_osmux_cn/

That config is used to control the use of osmux between BSC<->MSC. Since
we'll add support for Osmux in BTS<->BSC, we want to test that in a
separate way. Let's rename it so that we can add a "use_osmux_bts" later
on.

Change-Id: I3bde4e6772c18043dd763d7747b5dbe40e0da3b8
diff --git a/bsc/BSC_Tests_VAMOS.ttcn b/bsc/BSC_Tests_VAMOS.ttcn
index 6074fb2..131c2d4 100644
--- a/bsc/BSC_Tests_VAMOS.ttcn
+++ b/bsc/BSC_Tests_VAMOS.ttcn
@@ -298,8 +298,8 @@
 
 
 private function f_est_lchan_and_mode_modify_to_vamos() runs on MSC_ConnHdlr {
-	var PDU_BSSAP ass_cmd := f_gen_ass_req(g_pars.use_osmux);
-	var template PDU_BSSAP exp_compl := f_gen_exp_compl(g_pars.use_osmux);
+	var PDU_BSSAP ass_cmd := f_gen_ass_req(g_pars.use_osmux_cn);
+	var template PDU_BSSAP exp_compl := f_gen_exp_compl(g_pars.use_osmux_cn);
 
 	/* puzzle together the ASSIGNMENT REQ for given codec[s] */
 	if (mp_bssap_cfg[0].transport == BSSAP_TRANSPORT_AoIP) {