python - be: Use os.listdir, and only process files, so as not to try to

Log Message:
-----------
Use os.listdir, and only process files, so as not to try to test ./CVS/*.

Modified Files:
--------------
be/test:
regress.py (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/test/regress.py.diff?r1=1.1&r2=1.2)