Testsuite fixes.

Testsuite fixes.

* paxutils: Update.
* src/unlink.c (flush_deferred_unlinks): OpenSolaris sets EEXIST
instead of ENOTEMPTY if trying to remove a non-empty directory.
* tests/numeric.at: Avoid using awk -v: some older awks don't support
that option.  Also fix environment variable usage.
* tests/onetop05.at: Skip test if unable to set initial directory
mode bits.
* tests/sparse06.at: Use --quiet option.