no longer need xstats stub

(Logical change 1.77)
diff --git a/tc/q_tbf.c b/tc/q_tbf.c
index 01d514f..707d874 100644
--- a/tc/q_tbf.c
+++ b/tc/q_tbf.c
@@ -257,16 +257,9 @@
 	return 0;
 }
 
-static int tbf_print_xstats(struct qdisc_util *qu, FILE *f, struct rtattr *xstats)
-{
-	return 0;
-}
-
 struct qdisc_util tbf_util = {
-	NULL,
-	"tbf",
-	tbf_parse_opt,
-	tbf_print_opt,
-	tbf_print_xstats,
+	.id		= "tbf",
+	.parse_qopt	= tbf_parse_opt,
+	.print_qopt	= tbf_print_opt,
 };