fixing dhcp serialization problem

Change-Id: Ie049f9c1e464ca9a2b651df74f7b979628d0d745
diff --git a/openflow/api/src/main/java/org/onosproject/openflow/controller/DefaultOpenFlowPacketContext.java b/openflow/api/src/main/java/org/onosproject/openflow/controller/DefaultOpenFlowPacketContext.java
index da2bd16..238c400 100644
--- a/openflow/api/src/main/java/org/onosproject/openflow/controller/DefaultOpenFlowPacketContext.java
+++ b/openflow/api/src/main/java/org/onosproject/openflow/controller/DefaultOpenFlowPacketContext.java
@@ -104,7 +104,7 @@
         } catch (BufferUnderflowException | NullPointerException |
                 DeserializationException e) {
             Logger log = LoggerFactory.getLogger(getClass());
-            log.warn("packet deserialization problem");
+            log.warn("packet deserialization problem : {}", e.getMessage());
             return null;
         }
     }