Fix mistake in TopHits change

core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/TopHitsAggregatorBuilder.java

@@ -538,7 +538,7 @@ public class TopHitsAggregatorBuilder extends AggregatorBuilder<TopHitsAggregato
             factory.fieldNames = fieldNames;
         }
         factory.from = in.readVInt();
-        in.readOptionalWriteable(HighlightBuilder::new);
+        factory.highlightBuilder = in.readOptionalWriteable(HighlightBuilder::new);
         if (in.readBoolean()) {
             int size = in.readVInt();
             List<ScriptField> scriptFields = new ArrayList<>(size);

core/src/test/java/org/elasticsearch/search/aggregations/BaseAggregationTestCase.java

@@ -249,9 +249,9 @@ public abstract class BaseAggregationTestCase<AB extends AggregatorBuilder<AB>>
             try (StreamInput in = new NamedWriteableAwareStreamInput(StreamInput.wrap(output.bytes()), namedWriteableRegistry)) {
                 AggregatorBuilder deserializedQuery = namedWriteableRegistry.getReader(AggregatorBuilder.class, testAgg.getWriteableName())
                         .read(in);
-                assertEquals(deserializedQuery, testAgg);
-                assertEquals(deserializedQuery.hashCode(), testAgg.hashCode());
-                assertNotSame(deserializedQuery, testAgg);
+                assertEquals(testAgg, deserializedQuery);
+                assertEquals(testAgg.hashCode(), deserializedQuery.hashCode());
+                assertNotSame(testAgg, deserializedQuery);
             }
         }
     }