[Samba] open_fake_file access_denied file[$Extend/$Quota:$Q:$INDEX_ALLOCATION]

[Dragan Krnic]

By very few users the Samba log files get clogged with access_denied
messages at open_fake_file_shared every 15 minutes:

   smbd/fake_file.c:open_fake_file(114)
      open_fake_file_shared:
         access_denied to service[<aShare>]
            file[$Extend/$Quota:$Q:$INDEX_ALLOCATION]
               user[<aUser>]

open_fake_file fails with this error if the "current_user.ut.uid" is not
root, so either the user is trying to fetch information he is not entiteld
to or smbd under some circumstances fails to gain appropriate
privileges for this kind of access.