Windows: AFSSetDispositionInfo Verify Dir Enum

Before testing whether or not a directory is empty, the directory
must be enumerated.  If it is not, enumerate it.

Reviewed-on: http://gerrit.openafs.org/9780
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 9fd825790e4e61aa5fdf8996874fc9be8b1d1cc0)

Change-Id: I09d5e069e76162b605b2a9433c4b01c43842f159
Reviewed-on: http://gerrit.openafs.org/9817
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>