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.

1 files changed, 1 insertions, 1 deletions

diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index 707875d130d..5998ac8e395 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -1867,7 +1867,7 @@ It will be properly highlighted even when the call omits parens.")
       ("^[ \t]*def +\\(`\\)" (1 "_"))
       ;; Ternary operator colon followed by opening paren or bracket
       ;; (semi-important for indentation).
-      ("\\(:\\)\\(?:[\({]\\|\\[[^]]\\)"
+      ("\\(:\\)\\(?:[({]\\|\\[[^]]\\)"
        (1 (string-to-syntax ".")))
       ;; Regular expressions.  Start with matching unescaped slash.
       ("\\(?:\\=\\|[^\\]\\)\\(?:\\\\\\\\\\)*\\(/\\)"