bsc: fix f_establish_fully() for expected assignment failures

The altstep guard statements are to restrictive so they do not
match on an expected assignment failure anymore.

- Add a new altstep for expected assignment failures.

Change-Id: I78b839f0bcb7e2da61bff0add3abc452bfea40a2
diff --git a/bsc/MSC_ConnectionHandler.ttcn b/bsc/MSC_ConnectionHandler.ttcn
index a7f4d71..5a645bd 100644
--- a/bsc/MSC_ConnectionHandler.ttcn
+++ b/bsc/MSC_ConnectionHandler.ttcn
@@ -517,6 +517,7 @@
 	var PDU_BSSAP bssap;
 	timer T := 10.0;
 	var boolean exp_compl := ischosen(exp_ass_cpl.pdu.bssmap.assignmentComplete);
+	var boolean exp_fail := ischosen(exp_ass_cpl.pdu.bssmap.assignmentFailure);
 	var ExpectCriteria mgcpcrit := {
 		connid := omit,
 		endpoint := omit,
@@ -556,6 +557,9 @@
 	 (not st.is_assignment and st.modify_done)] BSSAP.receive(exp_ass_cpl) -> value bssap {
 		setverdict(pass);
 		}
+	[exp_fail] BSSAP.receive(exp_ass_cpl) -> value bssap {
+		setverdict(pass);
+		}
 	[(st.is_assignment and st.assignment_done or
 	 (not st.is_assignment and st.modify_done)) and
 	 exp_compl] BSSAP.receive(tr_BSSMAP_AssignmentComplete) {