hash array data - bug found by google error-prone

Change-Id: I0801f65264dc2be24f167b61c3b57772aa70a20b
diff --git a/utils/misc/src/main/java/org/onlab/packet/dhcp/DhcpOption.java b/utils/misc/src/main/java/org/onlab/packet/dhcp/DhcpOption.java
index a1b5923..8c637d0 100644
--- a/utils/misc/src/main/java/org/onlab/packet/dhcp/DhcpOption.java
+++ b/utils/misc/src/main/java/org/onlab/packet/dhcp/DhcpOption.java
@@ -141,7 +141,7 @@
      */
     @Override
     public int hashCode() {
-        return Objects.hash(code, length, data);
+        return Objects.hash(code, length, Arrays.hashCode(data));
     }
 
     /*