Windows: Fix smb_ReceiveTran2QPathInfo Pioctl support

Windows: Fix smb_ReceiveTran2QPathInfo Pioctl support

The path check should needs to include the root directory slash
when comparing to the \_._AFS_IOCTL_._ path to detect a pioctl
request.

Reviewed-on: http://gerrit.openafs.org/8488
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 eca3d56436c16e4634afe1954a2a15424b4ad5f1)

Change-Id: I201179644168cbc09a194612b2faf5bd3a812796
Reviewed-on: http://gerrit.openafs.org/8626
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>