Use dianmond operator

Change-Id: I551dd9443b10ef17832f74a554486b7605e9866a
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/NeighborSet.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/NeighborSet.java
index 7ada322..44715d2 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/NeighborSet.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/NeighborSet.java
@@ -44,7 +44,7 @@
     public NeighborSet(Set<DeviceId> neighbors) {
         checkNotNull(neighbors);
         this.edgeLabel = NO_EDGE_LABEL;
-        this.neighbors = new HashSet<DeviceId>();
+        this.neighbors = new HashSet<>();
         this.neighbors.addAll(neighbors);
     }
 
@@ -57,7 +57,7 @@
     public NeighborSet(Set<DeviceId> neighbors, int edgeLabel) {
         checkNotNull(neighbors);
         this.edgeLabel = edgeLabel;
-        this.neighbors = new HashSet<DeviceId>();
+        this.neighbors = new HashSet<>();
         this.neighbors.addAll(neighbors);
     }
 
@@ -66,7 +66,7 @@
      */
     public NeighborSet() {
         this.edgeLabel = NO_EDGE_LABEL;
-        this.neighbors = new HashSet<DeviceId>();
+        this.neighbors = new HashSet<>();
     }
 
     /**