PCUIF_Types: fix record PCUIF_data_cnf

The msg_id in record record PCUIF_data_cnf lacks the variant
BYTEORDER(last), (which we use in record PCUIF_agch and record
PCUIF_pch). This causes the msg_id to be sent back in the wrong
endieness format.

Related: OS#5927
Change-Id: I69c1ccc37dac1e06ebe29484c767014954ff55e2
diff --git a/library/PCUIF_Types.ttcn b/library/PCUIF_Types.ttcn
index b6a1bfa..6be45df 100644
--- a/library/PCUIF_Types.ttcn
+++ b/library/PCUIF_Types.ttcn
@@ -111,7 +111,9 @@
 type record PCUIF_data_cnf {
 	PCUIF_Sapi	sapi,
 	OCT4		msg_id
-} with { variant "" };
+} with {
+	variant (msg_id) "BYTEORDER(last)"
+};
 
 type record PCUIF_rts_req {
 	PCUIF_Sapi	sapi,