Windows: pioctl use GetFileAttributes

Windows: pioctl use GetFileAttributes

Instead of attempting to CreateFile(OPEN_EXISTING) the _._AFS_IOCTL_._
file, try using GetFileAttributes() to obtain the attributes of the
file.  The file doesn't exist in the directory listing but the
afs redirector and the afs smb server will respond to the request.
Perhaps the SMB servers in the broken printers will fail it.

Change-Id: I792bcc89c63871043ce6835a971de284fd754d54
Reviewed-on: http://gerrit.openafs.org/7210
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>