Fix libresolv initialization

Fixes: 9533031891 ("Update libresolv usage")

Signed-off-by: Youfu Zhang <zhangyoufu@gmail.com>

dns/transport/local/resolv_test.go

@@ -0,0 +1,13 @@
+package local
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestDNSReadConfig(t *testing.T) {
+	t.Parallel()
+	require.NoError(t, dnsReadConfig(context.Background(), "/etc/resolv.conf").err)
+}