python-native: distutils: don't use libdir, remove dead code path
* Coming from OE-classic it was surprising that python-native now
requires 'libdir' to be exported. Otherwise autoconf would fail
to detect python libraries. This happend using a customized
environment setup script to use OE's compiler and libs without
bitbake.
* Use STAGING_LIBDIR instead of libdir.
* While at it, remove redundant 'and' statments.
Signed-off-by: Andreas Oberritter <obi@opendreambox.org>
