Avoid NPE in AsterixHyracksIntegrationUtil.deinit

Change-Id: I4af385918becc2dfbc40462c9505135d91ea859f
Reviewed-on: https://asterix-gerrit.ics.uci.edu/1107
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Michael Blow <mblow@apache.org>
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/AsterixHyracksIntegrationUtil.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/AsterixHyracksIntegrationUtil.java
index b1bf418..03ed3c4 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/AsterixHyracksIntegrationUtil.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/AsterixHyracksIntegrationUtil.java
@@ -56,6 +56,7 @@
     private AsterixPropertiesAccessor propertiesAccessor;
 
     public void init(boolean deleteOldInstanceData) throws Exception {
+        ncs = new NodeControllerService[0]; // ensure that ncs is not null
         propertiesAccessor = new AsterixPropertiesAccessor();
         if (deleteOldInstanceData) {
             deleteTransactionLogs();