Convert to use rta_getattr_ functions

User new functions (inspired by libmnl) to do type safe access
of routeing attributes
diff --git a/tc/tc_filter.c b/tc/tc_filter.c
index d4b0b67..207302f 100644
--- a/tc/tc_filter.c
+++ b/tc/tc_filter.c
@@ -240,7 +240,7 @@
 				fprintf(fp, "pref %u ", prio);
 		}
 	}
-	fprintf(fp, "%s ", (char*)RTA_DATA(tb[TCA_KIND]));
+	fprintf(fp, "%s ", rta_getattr_str(tb[TCA_KIND]));
 	q = get_filter_kind(RTA_DATA(tb[TCA_KIND]));
 	if (tb[TCA_OPTIONS]) {
 		if (q)