; Replace (non-)nil with (non-)@code{nil} in texinfo files

; Replace (non-)nil with (non-)@code{nil} in texinfo files

* doc/lispref/functions.texi:
* doc/lispref/keymaps.texi:
* doc/lispref/strings.texi:
* doc/misc/cl.texi:
* doc/misc/dbus.texi:
* doc/misc/eshell.texi:
* doc/misc/message.texi:
* doc/misc/ses.texi:
* doc/misc/vtable.texi: Replace (non-)nil with (non-)@code{nil}.

(cherry picked from commit ecc8516d9ca17c70b4407296fa1140bb5e2b822c)