python: add explicit directories in py_package_preprocess
python: add explicit directories in py_package_preprocess

py_package_preprocess() was using relative paths which mean it depends on
exactly what directory it starts in.  To clarify the code, always use absolute
paths.

(Base on OE-Core rev: d9941a2d9b423af2ca3313e8c1357ccfcc9a96a5)

Signed-off-by: Trung Do <64081e6b7eb2b24289b8a4e51cef9836ddf28af2@toshiba-tsdv.com>

meta-debian/meta-debian,nghiaht-tsdv/meta-debian,nghiaht-tsdv/meta-debian,tienlee/meta-debian,meta-debian/meta-debian,tienlee/meta-debian,tienlee/meta-debian,meta-debian/meta-debian,nghiaht-tsdv/meta-debian,tienlee/meta-debian,meta-debian/meta-debian,tienlee/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,nghiaht-tsdv/meta-debian,tienlee/meta-debian,nghiaht-tsdv/meta-debian,nghiaht-tsdv/meta-debian