javadoc fixes

Change-Id: I3b4fc2d99f42b2413a535fb411b9c19bdd186ad8
diff --git a/utils/nio/src/main/java/org/onlab/nio/IOLoop.java b/utils/nio/src/main/java/org/onlab/nio/IOLoop.java
index 9d417ac..106df7b 100644
--- a/utils/nio/src/main/java/org/onlab/nio/IOLoop.java
+++ b/utils/nio/src/main/java/org/onlab/nio/IOLoop.java
@@ -107,6 +107,7 @@
      * Completes connection request pending on the given selection key.
      *
      * @param key selection key holding the pending connect operation.
+     * @throws IOException when I/O exception of some sort has occurred
      */
     protected void connect(SelectionKey key) throws IOException {
         SocketChannel ch = (SocketChannel) key.channel();