The ptest log will be saved to buildhistory/ptest, we can easily get
the regression result between builds by:
$ git show HEAD ptest/pass.fail.skip.*
[YOCTO #11547]
(From OE-Core rev: dcb6cd19fb8c639cb844d116fb83827267f37421)
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>