Bug fix in routing logic - should let routing process continue
if a particular route-path is ignored. Also added info logging for port-status
messages to clearly identify messages coming from the switch as opposed
to possibly fake updates generated by ONOS.

Change-Id: Ib03dfe0e2dcdcfb046d58657473fa4122ec15190
diff --git a/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java b/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
index 9844106..8b240e6 100644
--- a/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
+++ b/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
@@ -703,6 +703,11 @@
                 DeviceId targetSw = route.get(0);
                 DeviceId dstSw = route.get(1); // same as impactedDstDevice
                 Set<DeviceId> nextHops = getNextHops(targetSw, dstSw);
+                if (nextHops.isEmpty()) {
+                    log.warn("Could not find next hop from target:{} --> dst {} "
+                            + "skipping this route", targetSw, dstSw);
+                    continue;
+                }
                 Map<DeviceId, Set<DeviceId>> nhops = new HashMap<>();
                 nhops.put(dstSw, nextHops);
                 if (!populateEcmpRoutingRulePartial(targetSw, dstSw, null, nhops,