Windows: TRANS2_FIND_FIRST2 for _._AFS_IOCTL_._

Windows: TRANS2_FIND_FIRST2 for _._AFS_IOCTL_._

smb_T2SearchDirSingle() must not fail directory search requests
for the _._AFS_IOCTL_._ file.  Although this file does not actually
exist, it is successfully processed by CreateFile operations.
Therefore, an explicit search for it should return a valid answer.

Reviewed-on: http://gerrit.openafs.org/4884
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>
(cherry-picked from 9f77a2d6b3d571a928261563763913c8c6ee2938)

Change-Id: Iab58557350fa099c903b0c2b555e5cc2027daafc
Reviewed-on: http://gerrit.openafs.org/4894
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>