test: fix error in test/internet/test-dns.js

Refs: #35466 (comment)

PR-URL: #35969
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

test/internet/test-dns.js

@@ -401,7 +401,8 @@ TEST(function test_resolveSoa_failure(done) {
 
 TEST(async function test_resolveCaa(done) {
   function validateResult(result) {
-    assert.ok(Array.isArray(result[0]));
+    assert.ok(Array.isArray(result),
+              `expected array, got ${util.inspect(result)}`);
     assert.strictEqual(result.length, 1);
     assert.strictEqual(typeof result[0].critical, 'number');
     assert.strictEqual(result[0].critical, 0);