update

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
libcompel: Simplify approach

xemul@ said we don't need a heavy hammer here
so simply seize/unseize task. Sanity check is
up to a caller side.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>