fix exporting comments for function calls

Example of badly exported comment is this modified code
from autoinstallation, where comments are attached twice
(second node is `auto in return):

{

  textdomain "autoinst";

  if (!true)
        return `auto;

  list progress_stages = [];
  y2milestone(
   _("Installing image into system...%1%2%3%4%5"),
   "",     // progress_title
   size( progress_stages ),  // progress bar length
   progress_stages,
   "",
   "");

  return `next;

}
ignore temporary files from testsuite