Fix comment typo in the zookeeper lock recipe

Author: Kunal Parmar <kunalparmar@gmail.com>

Reviewers: symat@apache.org, fangmin@apache.org

Closes #1227 from kunalparmar/patch-1

zookeeper-recipes/zookeeper-recipes-lock/src/main/java/org/apache/zookeeper/recipes/lock/WriteLock.java

@@ -168,7 +168,7 @@ public class WriteLock extends ProtocolSupport {
     }
 
     /**
-     * a zoookeeper operation that is mainly responsible
+     * a zookeeper operation that is mainly responsible
      * for all the magic required for locking.
      */
     private class LockZooKeeperOperation implements ZooKeeperOperation {