bsc: add TC_ho_into_this_bsc_a5_mismatch

Since I just fixed the encryption behavior, I also want to know whether
the case of no A5 intersection is handled properly.

The tiny test comes with a lot of changes to allow a handover failure
code path. The 'expect_ho_fail' flag goes via function arguments to
g_pars and the general ho test code uses it to branch for exp-failure.

Related: SYS#5839
Change-Id: I44b464a0bedbff09c467c4bccd7c985480fb883a
diff --git a/bsc/MSC_ConnectionHandler.ttcn b/bsc/MSC_ConnectionHandler.ttcn
index e492ee0..29b7783 100644
--- a/bsc/MSC_ConnectionHandler.ttcn
+++ b/bsc/MSC_ConnectionHandler.ttcn
@@ -670,7 +670,8 @@
 	boolean		exp_fast_return, /* RR Release expected to contain CellSelectInd ? */
 	boolean		expect_channel_mode_modify,
 	uint3_t		expect_tsc optional,
-	BSSMAP_IE_CellIdentifier	cell_id_source
+	BSSMAP_IE_CellIdentifier	cell_id_source,
+	boolean		expect_ho_fail
 };
 
 /* Note: Do not use valueof() to get a value of this template, use
@@ -710,7 +711,8 @@
 	exp_fast_return := false,
 	expect_channel_mode_modify := false,
 	expect_tsc := omit,
-	cell_id_source := valueof(ts_CellID_LAC_CI(1, 1))
+	cell_id_source := valueof(ts_CellID_LAC_CI(1, 1)),
+	expect_ho_fail := false
 }
 
 function f_create_chan_and_exp(template (present) PDU_BSSAP exp_l3_compl := ?)