Windows: Handle invalid node types

Windows: Handle invalid node types

In the case where the direntry data is invalid, construct an Fcb
of type INVALID so that the direntry can be displayed and the objected
deleted even if it cannot be evaluated.

Change-Id: I37da154b7429929fe833874c7cd048a3a804a96f
Reviewed-on: http://gerrit.openafs.org/6445
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>