Backport commit 14d8b6858 from Emacs
* doc/org.texi (noweb-ref): Simplify shell script example and don’t
use ‘tail -1’, which is not portable.
Port and simplify example sh script
14d8b6858a49e97f9b69593df5a8a7886430d43f
Paul Eggert
Tue Mar 21 09:19:42 2017 -0700