Reduce scope of long-running memory-intensive unit test.

Change-Id: I0e76ed945757f8d907bb5507096a695986f19afe
diff --git a/core/store/serializers/src/test/java/org/onosproject/store/serializers/KryoSerializerTest.java b/core/store/serializers/src/test/java/org/onosproject/store/serializers/KryoSerializerTest.java
index 883892c..19abfba 100644
--- a/core/store/serializers/src/test/java/org/onosproject/store/serializers/KryoSerializerTest.java
+++ b/core/store/serializers/src/test/java/org/onosproject/store/serializers/KryoSerializerTest.java
@@ -380,7 +380,7 @@
     public void testMplsLabelResourceSet() {
         DiscreteResource port = Resources.discrete(DID1, P1).resource();
 
-        Set<DiscreteResource> labels = IntStream.range(0, 1024 * 1024)
+        Set<DiscreteResource> labels = IntStream.range(0, 1024)
                 .mapToObj(MplsLabel::mplsLabel)
                 .map(x -> Resources.discrete(port.id(), x).resource())
                 .collect(Collectors.toSet());