Windows: test for path in afs before symlink test

Windows: test for path in afs before symlink test

Check that the path is in afs before testing to see
if it is a symlink

Reviewed-on: http://gerrit.openafs.org/3467
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>
(cherry picked from commit f71219918e604a2909774e360cbfea9f9e3d9dcc)

Change-Id: I34191b8b67277f5cc8421323a1293c8ebd60c213
Reviewed-on: http://gerrit.openafs.org/3793
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>