A few tests were still manually cleaning their build paths, change them
to use package_qa_clean_path().
(From OE-Core rev: f6550c3ee1bc076015d85db36b3d281e6a7ace9d)
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>