Audit symbol quoting in Lisp doc strings

Audit symbol quoting in Lisp doc strings

* lisp/vc/vc-svn.el (vc-svn-dir-status-files):
* lisp/so-long.el (so-long-mode-maintain-preserved-variables):
* lisp/help-fns.el (help-fns--most-relevant-active-keymap):
* lisp/gnus/nnselect.el (nnselect-get-artlist):
(nnselect-store-artlist):
* lisp/forms.el (forms-enumerate):
* lisp/ffap.el (ffap-string-at-point):
* lisp/emacs-lisp/byte-run.el (define-obsolete-variable-alias):
Audit symbol quoting in Lisp doc strings.