Fix the issues reported by phpcs

Above error is fixed.

   if (!empty($font_paths) && is_array($font_paths)) {
-    _preload_fonts($font_paths, $attachments);
+    preload_font_preload_fonts($font_paths, $attachments);
   }

I can understand that _preload_fonts() could be a function implemented by a project whose machine name is preload_fonts, but functions are allowed to start with an underscore, and that is considered by the coding standards.