Delete redundant lambdas around unary functions

This is not just stylistic, but also slightly faster.  These are all
regular defuns, of course, as this won't work with macros and defsubsts.

* lisp/calc/calc-nlfit.el (math-nlfit-fit-curve)
(calc-fit-hubbert-linear-curve):
* lisp/calendar/cal-tex.el (cal-tex-latexify-list):
* lisp/calendar/todo-mode.el (todo-sort):
* lisp/cedet/semantic/ctxt.el (semantic-ctxt-end-of-symbol-default)
(semantic-ctxt-current-symbol-default):
* lisp/cedet/semantic/symref.el (semantic-symref-result-get-files):
* lisp/cedet/semantic/texi.el (semantic-texi-command-completion-list):
* lisp/descr-text.el (describe-char):
* lisp/emacs-lisp/eieio-datadebug.el
(data-debug-add-specialized-thing):
* lisp/emacs-lisp/rmc.el (read-multiple-choice--short-answers):
* lisp/eshell/em-pred.el (eshell-modifier-alist):
* lisp/gnus/gnus-cache.el (gnus-cache-articles-in-group):
* lisp/gnus/gnus-dired.el (gnus-dired-attach):
* lisp/help-mode.el (help-package-def):
* lisp/ibuf-ext.el (ibuffer-mark-modified-buffers):
* lisp/image/image-dired.el:
* lisp/international/quail.el (quail-keyseq-translate)
(quail-get-translations):
* lisp/isearch.el (isearch-pre-command-hook)
(search-within-boundaries):
* lisp/mail/supercite.el (sc-ask):
* lisp/mh-e/mh-e.el (mh-variant-set):
* lisp/net/rcirc.el (rcirc-nick-channels, rcirc-channel-nicks):
(rcirc-browse-url):
* lisp/obsolete/thumbs.el (thumbs-cleanup-thumbsdir):
* lisp/org/org-agenda.el (org-agenda-filter-completion-function):
* lisp/org/org-table.el (org-table-eval-formula):
* lisp/org/org.el (org-set-regexps-and-options):
* lisp/org/ox.el (org-export--get-inbuffer-options):
* lisp/ses.el (ses-range):
* lisp/textmodes/emacs-news-mode.el (emacs-news--buttonize):
* lisp/textmodes/ispell.el (ispell-begin-tex-skip-regexp):
* lisp/vc/vc-cvs.el (vc-cvs-stay-local-p):
* lisp/window.el (window--state-get-1):
* test/lisp/emacs-lisp/shortdoc-tests.el (shortdoc-all-groups-work):
Delete redundant lambdas around unary functions.  (Bug#66816)

test/lisp/emacs-lisp/shortdoc-tests.el

@@ -56,7 +56,7 @@
 
 (ert-deftest shortdoc-all-groups-work ()
   "Test that all defined shortdoc groups display correctly."
-  (dolist (group (mapcar (lambda (x) (car x)) shortdoc--groups))
+  (dolist (group (mapcar #'car shortdoc--groups))
     (let ((buf-name (format "*Shortdoc %s*" group)) buf)
       (unwind-protect
           (progn