f_perform_lu(): Use f_expect_clear(), reduce code duplication

Change-Id: I64b183ad6615f2b0b9565a711de87fe4249625a1
diff --git a/msc/BSC_ConnectionHandler.ttcn b/msc/BSC_ConnectionHandler.ttcn
index b3345ff..db0e683 100644
--- a/msc/BSC_ConnectionHandler.ttcn
+++ b/msc/BSC_ConnectionHandler.ttcn
@@ -384,9 +384,7 @@
 	f_expect_mm_info();
 
 	/* FIXME: there could be pending SMS or other common procedures by the MSC, let's ignore them */
-	BSSAP.receive(tr_BSSMAP_ClearCommand);
-	BSSAP.send(ts_BSSMAP_ClearComplete);
-	BSSAP.receive(RAN_Conn_Prim:MSC_CONN_PRIM_DISC_IND);
+	f_expect_clear();
 	setverdict(pass);
 }