Display custom post type only for logged in user

<?php
// Original http://pastie.org/1617402
// Original by David Smith, Ounce of Talent http://ounceoftalent.com/about/
// Modified by Chris Hajer October 7, 2012 for
// http://www.gravityhelp.com/forums/topic/drop-down-with-posts-from-certain-author#post-79310

/* Display Posts as Choices */

add_action('gform_pre_render', 'populate_post_type');
function populate_post_type($form){

    $dropdown_field = 2; // update to the ID of your drop down field
    $post_type = 'review'; // update

    $choices = ounce_posts_as_choices($post_type);

    foreach($form['fields'] as &$field){

        if($field['id'] == $dropdown_field)
            $field['choices'] = $choices;

    }

    return $form;
}

function ounce_posts_as_choices($post_type = 'post', $first_choice = '') {

    $posts = get_posts("post_type=$post_type");

    // determine the logged in user
    global $current_user;
    get_currentuserinfo();
    $userid = $current_user->ID;

    $choices = array();
    $i = 0;

    if($first_choice){
        $choices[$i]['text'] = $first_choice;
        $choices[$i]['value'] = '';
        $i++;
    }

    foreach($posts as $post) {
        // only return posts for the logged in user
        if ($userid == $post->post_author) {
            $choices[$i]['text'] = $post->post_title;
            $choices[$i]['value'] = $post->ID;
            $i++;
        }
    }

    return $choices;
}