Miscellaneous clean-up of provider IDs.

Change-Id: If7b3adf96425f8a655ea9af07b6da27a1a66a6f2
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java b/core/store/dist/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java
index f2e07f1..1850fa4 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java
@@ -48,6 +48,7 @@
 import static com.google.common.collect.ImmutableSetMultimap.Builder;
 import static org.onlab.graph.GraphPathSearch.Result;
 import static org.onlab.graph.TarjanGraphSearch.SCCResult;
+import static org.onlab.onos.core.CoreService.CORE_PROVIDER_ID;
 import static org.onlab.onos.net.Link.Type.INDIRECT;
 
 /**
@@ -61,8 +62,6 @@
     private static final TarjanGraphSearch<TopologyVertex, TopologyEdge> TARJAN =
             new TarjanGraphSearch<>();
 
-    private static final ProviderId PID = new ProviderId("core", "org.onlab.onos.net");
-
     private final long time;
     private final TopologyGraph graph;
 
@@ -296,7 +295,7 @@
         for (TopologyEdge edge : path.edges()) {
             links.add(edge.link());
         }
-        return new DefaultPath(PID, links, path.cost());
+        return new DefaultPath(CORE_PROVIDER_ID, links, path.cost());
     }