<?php
add_action( 'wp_footer', 'wpmudev_removedoubleddahs' );
function wpmudev_removedoubleddahs() {
    ?>
    <script type="text/javascript">
      jQuery(document).ready(function() {
        var val = jQuery(".mp_cart_resume_item_amount-total").html();
        jQuery(".mp_cart_resume_item_amount-total").html(val.substring(1, val.length));
        var val = jQuery(".mp_cart_coupon .mp_cart_resume_item_amount").html();
        jQuery(".mp_cart_coupon .mp_cart_resume_item_amount").html(val.substring(1, val.length));
      });
    </script>
    <?php
}