Fix error in tramp-archive-autoload-file-name-handler

Fix error in tramp-archive-autoload-file-name-handler

* lisp/net/tramp-archive.el (tramp-archive-autoload-file-name-handler):
Always call `tramp-autoload-file-name'.  Otherwise, when
`tramp-archive-enabled’ is nil and
`tramp-archive-autoload-file-name-handler’ is in the
`file-name-handler-alist’ results in an error “Invalid handler in
`file-name-handler-alist” once Emacs calls
`tramp-archive-autoload-file-name-handler’ with a handler that
does not expect nil.  Always returning nil is also false in
general.

Copyright-paperwork-exempt: yes