<header class="banner navbar navbar-default navbar-static-top" role="banner">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target=".navbar-collapse">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <img class="navbar-brand" src=" wp-content/themes/<?php echo get_template(); ?>/assets/img/xsce-draft-icon.png" style="padding-bottom: 20px; padding-top: 22px;"/>
      <a class="navbar-brand" href="<?php echo esc_url(home_url('/')); ?>"><?php bloginfo('name'); ?></a>
    </div>

    <nav class="collapse navbar-collapse" role="navigation">
      <?php
        if (has_nav_menu('primary_navigation')) :
          wp_nav_menu(array('theme_location' => 'primary_navigation', 'walker' => new Roots_Nav_Walker(), 'menu_class' => 'nav navbar-nav navbar-right'));
        endif;
      ?>
    </nav>
  </div>
</header>

<header class="banner navbar navbar-default navbar-static-top" role="banner">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target=".navbar-collapse">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <img class="navbar-brand" src="wp-content/themes/roots-master/assets/img/xsce-draft-icon.png" style="padding-bottom: 20px; padding-top: 22px;"/>
      <a class="navbar-brand" href="<?php echo esc_url(home_url('/')); ?>"><?php bloginfo('name'); ?></a>
    </div>

    <nav class="collapse navbar-collapse" role="navigation">
      <?php
        if (has_nav_menu('primary_navigation')) :
          wp_nav_menu(array('theme_location' => 'primary_navigation', 'walker' => new Roots_Nav_Walker(), 'menu_class' => 'nav navbar-nav navbar-right'));
        endif;
      ?>
    </nav>
  </div>
</header>

--- 
+++ 
@@ -7,7 +7,7 @@
         <span class="icon-bar"></span>
         <span class="icon-bar"></span>
       </button>
-      <img class="navbar-brand" src="wp-content/themes/roots-master/assets/img/xsce-draft-icon.png" style="padding-bottom: 20px; padding-top: 22px;"/>
+      <img class="navbar-brand" src=" wp-content/themes/<?php echo get_template(); ?>/assets/img/xsce-draft-icon.png" style="padding-bottom: 20px; padding-top: 22px;"/>
       <a class="navbar-brand" href="<?php echo esc_url(home_url('/')); ?>"><?php bloginfo('name'); ?></a>
     </div>
 
Fix path for xsce logo
