Windows: Ensure pResultCB exists before Authentication

When processing requests from the redirector it is possible for
the ResultCB to not be allocated.  This can occur either due to
an out of memory condition in a synchronous request or due to
an asynchronous extents or byte range lock request.

Move the assignment of the Authenticated state after the allocation
of the ResultCB from the stack in case of out of memory conditions.

Reviewed-on: http://gerrit.openafs.org/9110
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 7c31bd5e2d0da3a1c9e29337d5a90147f3b03158)

Change-Id: I498d49b49da2231f321fe811b514ad8c9e489792
Reviewed-on: http://gerrit.openafs.org/9117
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>