change MAC address hash to reduce collisions

Change-Id: I0ec7b53edcfce27508b0ea862da63597aa0ad3fd

@@ -188,7 +188,7 @@ public class MacAddress {
 
 
     @Override
     @Override
     public int hashCode() {
     public int hashCode() {
-        return Arrays.hashCode(this.address);
+        return Long.hashCode(toLong());
     }
     }
 
 
     @Override
     @Override