Short-code Inside Custom Post

function post_list_shortcode($atts){
	extract( shortcode_atts( array(
		'count' => '',
	), $atts) );
	
    $q = new WP_Query(
        array('posts_per_page' => $count, 'post_type' => 'posttype', 'orderby' => 'menu_order','order' => 'ASC')
        );		
		
	$list = '<div class="custom_post_list">';
	while($q->have_posts()) : $q->the_post();
		$idd = get_the_ID();
		$custom_field = get_post_meta($idd, 'custom_field', true);
        $post_content = get_the_content();
		$list .= '
		<div class="single_post_item">
            <h2>' .do_shortcode( get_the_title() ). '</h2>
			'.wpautop( $post_content ).'
            <p>'.$custom_field.'</p>
		</div>
		';        
	endwhile;
	$list.= '</div>';
	wp_reset_query();
	return $list;
}
add_shortcode('post_list', 'post_list_shortcode');