function wpogp_image_url()
{
    global $post;
    $image = get_the_post_thumbnail_src(get_the_post_thumbnail($post->ID));
    if (empty($image)) {
        return wpogp_image_url_default();
    } else {
        return $image;
    }
}
    <?php 
if (have_posts()) {
    while (have_posts()) {
        the_post();
        ?>
      <h1><?php 
        the_title();
        ?>
</h1>
     <section>
        <div class="row our-hotel">
          <div class="col-sm-6 col-lg-5 height-fix-to bckg-norepeat"<?php 
        if (has_post_thumbnail()) {
            ?>
            style="background-image:url(<?php 
            echo get_the_post_thumbnail_src(get_the_post_thumbnail($post_id, 'large'));
            ?>
)"
          <?php 
        }
        ?>
></div>
          <div class="col-sm-6 col-lg-offset-1 height-fix-from">
            <div class="container-half">
              <?php 
        if (get_field('about_granit_after_img')) {
            echo do_shortcode(get_field('about_granit_after_img'));
        }
        ?>
            </div>
          </div>
 function the_post_thumbnail_src($size = 'thumbnail')
 {
     echo get_the_post_thumbnail_src($size);
 }