Hide the posts created using a write panel

Hide the posts created using a write panel

function exclude_writepanels_posts($where){
    global $wpdb, $parent_file;

    if( $parent_file != 'edit.php' ) return $where;

    if (empty($_GET['filter-posts'])){
        $where = $where . " AND 0 = (SELECT count($wpdb->postmeta.meta_value)
				     FROM $wpdb->postmeta WHERE $wpdb->postmeta.post_id = $wpdb->posts.ID and $wpdb->postmeta.meta_key = '_mf_write_panel_id')";
    }	
    return $where;
}

add_filter('posts_where', 'exclude_writepanels_posts');