Revert "Fix afs_AccessOK for dropbox case"

Revert "Fix afs_AccessOK for dropbox case"

This reverts commit 3f89c0feae89e9a255afb8a7f08995412a3f1b79.

That change broke the expected semantics of a drop box, by
opening up read() access to users to whom it would usually be
denied. The expected dropbox behaviour is that whilst anyone
can write a file there, only those who are specifically given
r permissions may read it.

Change-Id: I025cef7cad1031fbed1e914d58a0a515561f3f78
Reviewed-on: http://gerrit.openafs.org/1149
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>