Shortcode to Query custom Post-type

Hi,

I followed this to add a content-block to my theme. I want to extend it with the Shortcodes.

I want to be able to write :
[content_zone name="col-1"]

The code should return the content of the content-block directly where the Shortcode is place within the page. My functions.php look as follows :

function content_zone_func( $atts ) {
	extract( shortcode_atts( array(
		'name' => ''
	), $atts ) );

	return get_content_zone($name);

}
function get_content_zone( $name ){

	$content_block = new WP_Query(array('post_type'=>'content-block', 'posts_per_page'=>1, 'content-position'=>$name));

	if($content_block->have_posts()){
		$content_block->the_post();
		$content = the_content();
		wp_reset_postdata();
	  	return $content;
	}
}
add_shortcode( 'content_zone', 'content_zone_func' );

The things return the good content but it is not placed correctly in the page. Let’s say I use this content in my page :

Hello, this is the content of the zone :
[content_zone name="col-1"]
There you go.

It would be posted like this on the page :

CONTENT OF THE ZONE

Hello, this is the content of the zone :
There you go.

It looks like the main loop is overrided by this secondary loop.

If I replace the function by simply returning a string, everything works fine.