virtiofsd has introduced killpriv_v2/no_killpriv_v2 for a while. Add
description of it to docs/helper.
Signed-off-by: Liu Yiding <liuyd.fnst@fujitsu.com>
Message-Id: <20220421095151.2231099-1-liuyd.fnst@fujitsu.com>
[Small documentation fixes: s/as client supports/as the client supports/
and s/. /. /.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>