[ONOS-2880] Initialize SuppressionRules before use

Change-Id: Icefce8109faa1732a5d2c7989695874775926977

@@ -239,6 +239,7 @@ public class LLDPLinkProvider extends AbstractProvider implements LinkProvider {
         deviceService.addListener(deviceListener);
         packetService.addProcessor(packetProcessor, PacketProcessor.advisor(0));
 
+        loadSuppressionRules();
         loadDevices();
 
         executor = newSingleThreadScheduledExecutor(groupedThreads("onos/link", "discovery-%d"));
@@ -247,7 +248,6 @@ public class LLDPLinkProvider extends AbstractProvider implements LinkProvider {
         executor.scheduleAtFixedRate(new LinkPrunerTask(),
                                      LINK_PRUNER_DELAY, LINK_PRUNER_DELAY, SECONDS);
 
-        loadSuppressionRules();
         requestIntercepts();
     }
 

@@ -104,8 +104,12 @@ class LinkDiscovery implements TimerTask {
     }
 
     synchronized void stop() {
+        if (!isStopped) {
             isStopped = true;
             timeout.cancel();
+        } else {
+            log.warn("LinkDiscovery stopped multiple times?");
+        }
     }
 
     synchronized void start() {