add_filter('manage_posts_columns', 'posts_column_views');
add_action('manage_posts_custom_column', 'posts_custom_column_views',5,2);
 
function posts_column_views($defaults){
    $defaults['post_views'] = __('Views');
    return $defaults;
}
function posts_custom_column_views($column_name, $id){
    if($column_name === 'post_views'){
        echo getPostViews(get_the_ID());
    }
}