bitbake-setup deduces top directory from BBPATH, which, if set, interferes with
the tests' own setup.
(Bitbake rev: e974d42eb5229f755e14b46a00ad06b23b53e143)
Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>