s3: smbd: Change is_visible_file() to take a directory handle not a name.

s3: smbd: Change is_visible_file() to take a directory handle not a name.

No change in functionality as the name is
easily retrieved from the directory handle
(it's always the name we opened the directory with)
and this will allow us to use the directory handle
fsp later.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>