[ONOS-6284] Pointer passed to method where it is dereferened can be null

Change-Id: I9dd4b02888e39151030afc0da91bb648c34ca053
diff --git a/apps/tetopology/app/src/main/java/org/onosproject/tetopology/management/impl/DistributedTeTopologyStore.java b/apps/tetopology/app/src/main/java/org/onosproject/tetopology/management/impl/DistributedTeTopologyStore.java
index 3d6be15..151df3d 100644
--- a/apps/tetopology/app/src/main/java/org/onosproject/tetopology/management/impl/DistributedTeTopologyStore.java
+++ b/apps/tetopology/app/src/main/java/org/onosproject/tetopology/management/impl/DistributedTeTopologyStore.java
@@ -1004,6 +1004,12 @@
         }
         // Then remove it from teNodeMap
         InternalTeNode node = teNodeMap.remove(nodeKey);
+
+        if (node == null) {
+            log.error("No node found for nodeKey {}", nodeKey);
+            return;
+        }
+
         removeTeNodeMapEntrys(node);
         // Remove it from networkNodeMap
         if (teNodeRemove && node != null) {