Update test

Author: MattAlp

server/src/internalClusterTest/java/org/elasticsearch/search/aggregations/bucket/ReverseNestedIT.java

@@ -470,15 +470,19 @@ public void testReverseNestedAggWithoutNestedAgg() {
     public void testNonExistingNestedField() throws Exception {
         assertNoFailuresAndResponse(
             prepareSearch("idx2").setQuery(matchAllQuery())
-                .addAggregation(nested("nested2", "nested1.nested2").subAggregation(reverseNested("incorrect").path("nested3"))),
+                .addAggregation(nested("nested2", "nested1.nested2"))
+                .addAggregation(nested("incorrect", "nested1.incorrect")),
             response -> {
 
                 SingleBucketAggregation nested = response.getAggregations().get("nested2");
                 assertThat(nested, notNullValue());
                 assertThat(nested.getName(), equalTo("nested2"));
+                assertThat(nested.getDocCount(), is(27L));
 
-                SingleBucketAggregation reverseNested = nested.getAggregations().get("incorrect");
-                assertThat(reverseNested.getDocCount(), is(0L));
+                SingleBucketAggregation incorrect = response.getAggregations().get("incorrect");
+                assertThat(incorrect, notNullValue());
+                assertThat(incorrect.getName(), equalTo("incorrect"));
+                assertThat(incorrect.getDocCount(), is(0L));
             }
         );