msc: check IMEI: move reject LU into new function

Change-Id: Ifad259e21df035a89e97831a57c0675502308eb6
diff --git a/msc/BSC_ConnectionHandler.ttcn b/msc/BSC_ConnectionHandler.ttcn
index e951400..fb2d888 100644
--- a/msc/BSC_ConnectionHandler.ttcn
+++ b/msc/BSC_ConnectionHandler.ttcn
@@ -642,6 +642,24 @@
 	setverdict(pass);
 }
 
+function f_expect_lu_reject() runs on BSC_ConnHdlr {
+	var PDU_DTAP_MT dtap_mt;
+	timer T := 5.0;
+
+	T.start;
+	alt {
+	[] BSSAP.receive(tr_PDU_DTAP_MT(tr_ML3_MT_LU_Rej)) {
+		setverdict(pass);
+		}
+	[] BSSAP.receive(tr_PDU_DTAP_MT(?)) -> value dtap_mt {
+		setverdict(fail, "Expected LU reject BSSAP message, got: ", dtap_mt);
+		}
+	[] T.timeout {
+		setverdict(fail, "Timeout waiting for LU reject");
+		}
+	}
+}
+
 function f_foo() runs on BSC_ConnHdlr{
 	/* SCCP CC handled by RAN_Emulation_CT.main() */
 	/* Expect auth, if enabled */