bts: fix TC_dyn_osmo_pdch_unsol_deact

TC_dyn_osmo_pdch_unsol_deact sends a release request on an already released
lchan, which obviously would never trigger a change in the PCU configuration
and hence it makes no sense to expect a PCU info ind to be sent.

Instead of f_dyn_osmo_pdch_deact(), which expects a PCU info_ind, just send a
CHAN_REL and expect a trivial REL_ACK.

Drop some unused local vars.

Change-Id: I6b790e866ce4e66d9385b286b727ae41a83d3e67
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 5e93ba3..8379fba 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -2732,14 +2732,13 @@
 /* send a RF CHAN REL for PDCH on an osmocom dynamci PDCH that's already inactive */
 function f_TC_dyn_osmo_pdch_unsol_deact(charstring id) runs on ConnHdlr {
 	var PCUIF_Message first_info;
-	var integer ts_nr := g_chan_nr.tn;
-	var integer trx_nr := 0;
-	var integer bts_nr := 0;
 	var integer pcu_conn_id := -1;
 
 	f_init_pcu(PCU, id, pcu_conn_id, first_info);
 
-	f_dyn_osmo_pdch_deact(pcu_conn_id, bts_nr, trx_nr);
+	RSL.send(ts_RSL_RF_CHAN_REL(g_chan_nr));
+	/* since the lchan is already released, we don't expect any PCU changes, just a rel ack. */
+	RSL.receive(tr_RSL_RF_CHAN_REL_ACK(g_chan_nr));
 	setverdict(pass);
 }
 testcase TC_dyn_osmo_pdch_unsol_deact() runs on test_CT {