detected by clang.

Change-Id: Id9effcc5437870f37fecd33803f7753c6eca53d6
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/361


Tested-by: jenkins
Reviewed-by: Øyvind Harboe <oyvindharboe@gmail.com>
Reviewed-by: Mathias Küster <kesmtp@freenet.de>