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

Change-Id: I0a1aea4bdb5d305c50273e6ff749fe71bd2a295a
diff --git a/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackRoutingManager.java b/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackRoutingManager.java
index 970a331..b6aeab9 100644
--- a/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackRoutingManager.java
+++ b/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackRoutingManager.java
@@ -215,7 +215,7 @@
                         .filter(h -> routableNetIds.contains(h.annotations().value(NETWORK_ID)))
                         .collect(Collectors.toSet());
 
-        hosts.stream().forEach(h -> populateRoutingRules(h, routableNets));
+        hosts.forEach(h -> populateRoutingRules(h, routableNets));
     }
 
     private void unsetRoutes(OpenstackRouter osRouter, OpenstackNetwork osNet) {
@@ -226,7 +226,7 @@
                         h.annotations().value(NETWORK_ID), osNet.id()))
                 .forEach(h -> removeRoutingRules(h, routableNets));
 
-        routableNets.stream().forEach(n -> {
+        routableNets.forEach(n -> {
             Tools.stream(hostService.getHosts())
                     .filter(h -> Objects.equals(
                             h.annotations().value(NETWORK_ID),
@@ -269,7 +269,7 @@
                 .matchTunnelId(Long.valueOf(osNet.segmentId()))
                 .matchEthDst(Constants.DEFAULT_GATEWAY_MAC);
 
-        nodeService.completeNodes().stream().forEach(node -> {
+        nodeService.completeNodes().forEach(node -> {
             ForwardingObjective.Flag flag = node.type().equals(GATEWAY) ?
                     ForwardingObjective.Flag.VERSATILE :
                     ForwardingObjective.Flag.SPECIFIC;
@@ -359,8 +359,7 @@
                 .fromApp(appId)
                 .add();
 
-        gatewayService.getGatewayDeviceIds().stream()
-                .forEach(deviceId -> flowObjectiveService.forward(deviceId, fo));
+        gatewayService.getGatewayDeviceIds().forEach(deviceId -> flowObjectiveService.forward(deviceId, fo));
     }
 
     private void populateCnodeToGateway(long vni) {
diff --git a/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSecurityGroupManager.java b/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSecurityGroupManager.java
index e06b7fa..9b15f00 100644
--- a/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSecurityGroupManager.java
+++ b/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSecurityGroupManager.java
@@ -121,7 +121,7 @@
                 .filter(entry -> getTenantId(entry.getKey()).equals(tenantId))
                 .forEach(entry -> {
                     Host local = entry.getKey();
-                    entry.getValue().stream().forEach(sgRule -> {
+                    entry.getValue().forEach(sgRule -> {
                         setSecurityGroupRule(local.location().deviceId(),
                                 sgRule.rule(),
                                 getIp(local),
@@ -250,10 +250,10 @@
         }
 
         Set<SecurityGroupRule> rules = Sets.newHashSet();
-        osPort.securityGroups().stream().forEach(sgId -> {
+        osPort.securityGroups().forEach(sgId -> {
             OpenstackSecurityGroup osSecGroup = openstackService.securityGroup(sgId);
             if (osSecGroup != null) {
-                osSecGroup.rules().stream().forEach(rule -> rules.addAll(getSgRules(rule)));
+                osSecGroup.rules().forEach(rule -> rules.addAll(getSgRules(rule)));
             } else {
                 // TODO handle the case that the security group removed
                 log.warn("Failed to get security group {}", sgId);
diff --git a/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSwitchingArpHandler.java b/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSwitchingArpHandler.java
index c35371f..d70524c 100644
--- a/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSwitchingArpHandler.java
+++ b/apps/openstacknetworking/switching/src/main/java/org/onosproject/openstacknetworking/switching/OpenstackSwitchingArpHandler.java
@@ -194,8 +194,7 @@
             log.warn("Failed to get OpenStack network for {}", host);
             return;
         }
-        osNet.subnets().stream()
-                .forEach(subnet -> gateways.add(Ip4Address.valueOf(subnet.gatewayIp())));
+        osNet.subnets().forEach(subnet -> gateways.add(Ip4Address.valueOf(subnet.gatewayIp())));
     }
 
     @Override