test: add t.Helper() calls to test helper functions (#7351)

plugin/dnstap/handler_test.go

@@ -14,6 +14,7 @@ import (
 )
 
 func testCase(t *testing.T, tapq, tapr *tap.Dnstap, q, r *dns.Msg, extraFormat string) {
+	t.Helper()
 	w := writer{t: t}
 	w.queue = append(w.queue, tapq, tapr)
 	h := Dnstap{

plugin/dnstap/io_test.go

@@ -18,6 +18,7 @@ var (
 )
 
 func accept(t *testing.T, l net.Listener, count int) {
+	t.Helper()
 	server, err := l.Accept()
 	if err != nil {
 		t.Fatalf("Server accepted: %s", err)