Import proposed fix from
https://github.com/jmmv/atf/commit/0e546407567ea858e261e72f75c5ed61e07d0ddf.patch

PR: 197060

Original commit message:

From 0e546407567ea858e261e72f75c5ed61e07d0ddf Mon Sep 17 00:00:00 2001
From: Julio Merino <jmmv@google.com>
Date: Tue, 17 Feb 2015 18:10:11 -0500
Subject: [PATCH] Fix atf-sh/atf_check_test:flush_stdout_on_death

The test atf-sh/atf_check_test:flush_stdout_on_timeout was flaky as it
was playing solely with time. Fix this by making the test more robust
and rename it while we are at it: there is nothing left about "timeouts"
in this test, considering that ATF itself does not enforce deadlines
any longer.

Fixes FreeBSD PR 197060.