fixed format

diff --git a/skeletons/constr_CHOICE.c b/skeletons/constr_CHOICE.c
index 4ac71a6..140e365 100644
--- a/skeletons/constr_CHOICE.c
+++ b/skeletons/constr_CHOICE.c
@@ -516,7 +516,7 @@
 		}
 	} else {
 		_ASN_ERRLOG(app_errlog, app_key,
-			"%s: no CHOICE element given",
+			"%s: no CHOICE element given (%s:%d)",
 			td->name, __FILE__, __LINE__);
 		return -1;
 	}