Fix potential class cast exception in UnorderedListTypeDefinition

Change-Id: I583d681ffe84bd73eebcb4acd07062f6b4a1460e
Reviewed-on: https://asterix-gerrit.ics.uci.edu/1794
Reviewed-by: Yingyi Bu <buyingyi@gmail.com>
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
BAD: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
diff --git a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/expression/UnorderedListTypeDefinition.java b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/expression/UnorderedListTypeDefinition.java
index ad6426e..48be7d2 100644
--- a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/expression/UnorderedListTypeDefinition.java
+++ b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/expression/UnorderedListTypeDefinition.java
@@ -54,7 +54,7 @@
         if (this == object) {
             return true;
         }
-        if (!(object instanceof OrderedListTypeDefinition)) {
+        if (!(object instanceof UnorderedListTypeDefinition)) {
             return false;
         }
         UnorderedListTypeDefinition target = (UnorderedListTypeDefinition) object;