Javadoc fixes.

Change-Id: Ic2cef19a6f1af9916c8615c9319cc122d9da5383
diff --git a/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowModBuilderVer13.java b/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowModBuilderVer13.java
index f2ad959..6de56c3 100644
--- a/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowModBuilderVer13.java
+++ b/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowModBuilderVer13.java
@@ -70,6 +70,7 @@
      *
      * @param flowRule the flow rule to transform into a flow mod
      * @param factory the OpenFlow factory to use to build the flow mod
+     * @param xid the transaction ID
      */
     protected FlowModBuilderVer13(FlowRule flowRule, OFFactory factory, Optional<Long> xid) {
         super(flowRule, factory, xid);