Renamed Trie to Tree for consistency.

This is in the context of SDN-IP's patricia tree.

Change-Id: I59437fb49580aba01a287e9bc0bf035c093c7b95
diff --git a/src/main/java/net/onrc/onos/apps/bgproute/IBgpRouteService.java b/src/main/java/net/onrc/onos/apps/bgproute/IBgpRouteService.java
index fa2d3fc..effc81b 100644
--- a/src/main/java/net/onrc/onos/apps/bgproute/IBgpRouteService.java
+++ b/src/main/java/net/onrc/onos/apps/bgproute/IBgpRouteService.java
@@ -15,7 +15,7 @@
      *
      * @return the PATRICIA tree.
      */
-    public IPatriciaTrie<RibEntry> getPtree();
+    public IPatriciaTree<RibEntry> getPtree();
 
     /**
      * Gets the IP address of REST server on the BGPd side. This is used to