sys: pioctl_nt translate WinErr to Unix

When reading the result of a pioctl fails with ERROR_NOT_SUPPORTED
this must be translated to an EINVAL errno.

Reviewed-on: http://gerrit.openafs.org/11417
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 1ce48e9e93c686aef24bb066ce76c2fcf08f96b6)

Change-Id: I4ffc910b4b0053bf7895b0b6aa48826ee7a8d2ea
Reviewed-on: http://gerrit.openafs.org/11421
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>