Make the doc clear for `findORCreate` cb

lib/persisted-model.js

@@ -143,7 +143,7 @@ module.exports = function(registry) {
    * @callback {Function} callback Callback function called with `cb(err, instance, created)` arguments.  Required.
    * @param {Error} err Error object; see [Error object](http://docs.strongloop.com/display/LB/Error+object).
    * @param {Object} instance Model instance matching the `where` filter, if found.
-   * @param {Boolean} created True if the instance matching the `where` filter was created.
+   * @param {Boolean} created True if the instance does not exist and gets created.
    */
 
   PersistedModel.findOrCreate = function findOrCreate(query, data, callback) {