pcuif: make variable const

Change-Id: I0450a49a4c9a8e0e1252d6561fb93f6fb4585748
diff --git a/pcu/PCUIF_Components.ttcn b/pcu/PCUIF_Components.ttcn
index 7655184..27cf56d 100644
--- a/pcu/PCUIF_Components.ttcn
+++ b/pcu/PCUIF_Components.ttcn
@@ -505,7 +505,7 @@
 			u := { info_ind := info_ind }
 		});
 
-		var integer start_fn := 0;
+		const integer start_fn := 0;
 		if (mp_send_all_data_ind) {
 			f_tx_first_data_ind(bts_nr, info_ind, start_fn);
 		}