The usleep is only provided on distros from Redhat so running ftracetest
on other distro resulted in failures due to the missing usleep.

The reason of using [u]sleep in the test was to generate (scheduler)
events.  It can be done various ways like this:

yield() {  ping localhost -c 1 || sleep .001 || usleep 1 || sleep 1; }

For more information to the history of this patch, please refer to:

Link: http://lkml.kernel.org/r/1427329943-16896-1-git-send-email-namhyung@kernel.orgReported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Luis Henriques <luis.henriques@canonical.com>
Suggested-by: Pádraig Brady <P@draigBrady.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>