Delete redundant lambdas around unary functions

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)

(cherry picked from commit 0e76716c5faa5e91ac3913b02ba4dc690cf5df83)