Replace manual hash code calculation for long with Long.hashCode(long)

Change-Id: Ie588a2904e0fcc790282af22912e8ff6d7a31648
diff --git a/core/api/src/main/java/org/onosproject/net/intent/IntentId.java b/core/api/src/main/java/org/onosproject/net/intent/IntentId.java
index e2bf307..b3077c5 100644
--- a/core/api/src/main/java/org/onosproject/net/intent/IntentId.java
+++ b/core/api/src/main/java/org/onosproject/net/intent/IntentId.java
@@ -60,7 +60,7 @@
 
     @Override
     public int hashCode() {
-        return (int) (value ^ (value >>> 32));
+        return Long.hashCode(value);
     }
 
     @Override
diff --git a/core/api/src/main/java/org/onosproject/net/intent/Key.java b/core/api/src/main/java/org/onosproject/net/intent/Key.java
index dc9ef36..8420188 100644
--- a/core/api/src/main/java/org/onosproject/net/intent/Key.java
+++ b/core/api/src/main/java/org/onosproject/net/intent/Key.java
@@ -42,7 +42,7 @@
 
     @Override
     public int hashCode() {
-        return (int) (hash() ^ (hash() >>> 32));
+        return Long.hashCode(hash);
     }
 
     @Override
diff --git a/core/api/src/main/java/org/onosproject/net/tunnel/TunnelId.java b/core/api/src/main/java/org/onosproject/net/tunnel/TunnelId.java
index 50e56f7..ca57797 100644
--- a/core/api/src/main/java/org/onosproject/net/tunnel/TunnelId.java
+++ b/core/api/src/main/java/org/onosproject/net/tunnel/TunnelId.java
@@ -65,7 +65,7 @@
 
     @Override
     public int hashCode() {
-        return (int) (value ^ (value >>> 32));
+        return Long.hashCode(value);
     }
 
     @Override
diff --git a/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java b/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java
index cbfaa3e..6e0f65b 100644
--- a/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java
+++ b/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java
@@ -91,9 +91,7 @@
 
     @Override
     public int hashCode() {
-        int hash = 17;
-        hash += 31 * hash + (int) (value ^ value >>> 32);
-        return hash;
+        return Long.hashCode(value);
     }
 
     /**
diff --git a/utils/misc/src/main/java/org/onlab/packet/ChassisId.java b/utils/misc/src/main/java/org/onlab/packet/ChassisId.java
index 0d9f955..23c9859 100644
--- a/utils/misc/src/main/java/org/onlab/packet/ChassisId.java
+++ b/utils/misc/src/main/java/org/onlab/packet/ChassisId.java
@@ -81,8 +81,6 @@
 
     @Override
     public int hashCode() {
-        int hash = 17;
-        hash += 31 * hash + (int) (value ^ value >>> 32);
-        return hash;
+        return Long.hashCode(value);
     }
 }