Fixes [YOCTO #4975]
Changes made to be sure that we are not assuming WORKDIR is a
child of the 'S' directory.
(From yocto-docs rev: c47b65c008ee45873e3bf61c7aaea18ca9744007)
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>