Use Collection#forEach() instead of Stream#forEach() for simplicity

Change-Id: I0a1aea4bdb5d305c50273e6ff749fe71bd2a295a
diff --git a/core/net/src/test/java/org/onosproject/cluster/impl/MastershipManagerTest.java b/core/net/src/test/java/org/onosproject/cluster/impl/MastershipManagerTest.java
index 39d9e0d..0e6ef61 100644
--- a/core/net/src/test/java/org/onosproject/cluster/impl/MastershipManagerTest.java
+++ b/core/net/src/test/java/org/onosproject/cluster/impl/MastershipManagerTest.java
@@ -307,7 +307,7 @@
     private void checkDeviceMasters(Set<DeviceId> deviceIds, Set<NodeId> expectedMasters,
                                      Consumer<DeviceId> checkRole) {
         // each device's master must be contained in the list of expectedMasters
-        deviceIds.stream().forEach(deviceId -> {
+        deviceIds.forEach(deviceId -> {
             assertTrue("wrong master:", expectedMasters.contains(mgr.getMasterFor(deviceId)));
             if (checkRole != null) {
                 checkRole.accept(deviceId);