Further doc string quoting fixes

Further doc string quoting fixes

* test/lisp/progmodes/cperl-mode-tests.el (cperl--run-test-cases):
* lisp/simple.el (undo-equiv-table):
* lisp/shell.el (shell-mode):
(shell-mode):
* lisp/recentf.el (recentf-mode):
* lisp/org/ob-table.el (org-sbe):
* lisp/net/eudc.el (eudc-rfc5322-cctext-token):
* lisp/mail/ietf-drums-date.el (ietf-drums-date--slot-ranges):
* lisp/faces.el (color-luminance-dark-limit):
* lisp/erc/erc.el (erc-tls):
* lisp/emacs-lisp/pcase.el (pcase-setq): Further quoting fixes in
doc strings.