Fix some ineffective backslashes in string literals

Deal with lone backslashes that have no effect in string literals,
but indicate that something is amiss.

* lisp/auth-source-pass.el (auth-source-pass-entries):
* lisp/textmodes/artist.el (artist-figlet-get-font-list-windows):
* lisp/org/ob-abc.el (org-babel-expand-body:abc, org-babel-execute:abc):
* lisp/org/ob-forth.el (org-babel-forth-session-execute):
* lisp/vc/vc-git.el (vc-git--program-version):
Add backslash in regexp for correctness.

* lisp/gnus/nnmail.el (nnmail-split-abbrev-alist):
Replace `\||' with `\\|' to follow the obvious regexp intent.

* lisp/org/org-list.el (org-plain-list-ordered-item-terminator):
Add backslash in doc comment so that it appears as intended.

* lisp/progmodes/cc-engine.el (c-forward-decl-or-cast-1, c-end-of-decl-1):
* lisp/progmodes/f90.el (f90-font-lock-keywords-2):
* lisp/progmodes/etags.el (etags-tags-completion-table):
* lisp/progmodes/ruby-mode.el (ruby-syntax-propertize):
* test/lisp/emacs-lisp/cl-print-tests.el (cl-print-tests-1):
Remove superfluous backslashes from regexp.

* test/lisp/emacs-lisp/rx-tests.el (rx-char-any):
Remove superfluous backslash from doc comment.

2 files changed, 2 insertions, 2 deletions

diff --git a/test/lisp/emacs-lisp/cl-print-tests.el b/test/lisp/emacs-lisp/cl-print-tests.el
index e163fb8a8dd..406c528dce5 100644
--- a/test/lisp/emacs-lisp/cl-print-tests.el
+++ b/test/lisp/emacs-lisp/cl-print-tests.el
@@ -34,7 +34,7 @@
     (let ((print-circle t))
       (should (equal (cl-prin1-to-string `((x . ,x) (y . ,x)))
                      "((x . #1=#s(cl-print--test :a 1 :b 2)) (y . #1#))")))
-    (should (string-match "\\`#f(compiled-function (x) \"[^\"]+\" [^\)]*)\\'"
+    (should (string-match "\\`#f(compiled-function (x) \"[^\"]+\" [^)]*)\\'"
                           (cl-prin1-to-string (symbol-function #'caar))))))
 
 (ert-deftest cl-print-tests-2 ()
diff --git a/test/lisp/emacs-lisp/rx-tests.el b/test/lisp/emacs-lisp/rx-tests.el
index fa3d9b0d5ea..7dd5e3b8de9 100644
--- a/test/lisp/emacs-lisp/rx-tests.el
+++ b/test/lisp/emacs-lisp/rx-tests.el
@@ -25,7 +25,7 @@
 ;;; Code:
 
 (ert-deftest rx-char-any ()
-  "Test character alternatives with `\]' and `-' (Bug#25123)."
+  "Test character alternatives with `]' and `-' (Bug#25123)."
   (should (string-match
            (rx string-start (1+ (char (?\] . ?\{) (?< . ?\]) (?- . ?:)))
                string-end)