Remove (or double) redundant backslashes in string literals
See discussion at https://lists.gnu.org/archive/html/emacs-devel/2020-01/msg00749.html . * lisp/obsolete/iswitchb.el (iswitchb-summaries-to-end): * test/src/regex-emacs-tests.el (regex-tests-BOOST-frob-escapes): * test/lisp/help-fns-tests.el (help-fns-test-lisp-macro) (help-fns-test-lisp-defun, help-fns-test-lisp-defsubst) (help-fns-test-alias-to-defun, help-fns-test-bug23887): Double backslashes for desired effect. * lisp/org/ol.el (org-link-escape): * lisp/net/nsm.el (nsm-protocol-check--rsa-kx) (nsm-protocol-check--anon-kx, nsm-protocol-check--sha1-sig): * lisp/obsolete/old-whitespace.el (whitespace-buffer): * lisp/obsolete/rcompile.el (remote-compile-run-before): * lisp/obsolete/vi.el (vi-end-of-blank-delimited-word): * lisp/obsolete/vip.el (vip-current-major-mode) (vip-paren-match, vip-switch-to-buffer) (vip-switch-to-buffer-other-window, vip-kill-buffer) (vip-get-ex-token, ex-edit): * lisp/org/org-element.el (org-element--cache-sync-requests): * lisp/org/org.el (org-sparse-tree): * lisp/textmodes/reftex.el (reftex-report-bug): * test/lisp/ibuffer-tests.el (ibuffer-save-filters): * test/lisp/international/ucs-normalize-tests.el (ucs-normalize-tests--insert-failing-lines): * test/lisp/simple-tests.el (undo-test-kill-c-a-then-undo): * test/lisp/textmodes/conf-mode-tests.el (conf-test-toml-mode): * test/src/regex-emacs-tests.el (regex-tests-compare): Remove redundant backslashes.