javadoc fixes

Change-Id: I3b4fc2d99f42b2413a535fb411b9c19bdd186ad8
diff --git a/core/api/src/main/java/org/onlab/onos/net/statistic/StatisticStore.java b/core/api/src/main/java/org/onlab/onos/net/statistic/StatisticStore.java
index 29eced7..96fcc11 100644
--- a/core/api/src/main/java/org/onlab/onos/net/statistic/StatisticStore.java
+++ b/core/api/src/main/java/org/onlab/onos/net/statistic/StatisticStore.java
@@ -34,7 +34,7 @@
 
     /**
      * Remove entries associated with this rule.
-     a @param rule {@link org.onlab.onos.net.flow.FlowRule}
+     * @param rule {@link org.onlab.onos.net.flow.FlowRule}
      */
     void removeFromStatistics(FlowRule rule);