Fix some file-mode races

* lisp/emacs-lisp/autoload.el (autoload-ensure-file-writeable):
* lisp/files.el (after-find-file):
* lisp/gnus/gnus-start.el (gnus-dribble-read-file):
* lisp/htmlfontify.el (hfy-copy-and-fontify-file):
* lisp/server.el (server-ensure-safe-dir):
Avoid a race when getting file permissions.
1 job for master in 55 minutes and 34 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Test
passed #3325
test-all

00:55:34