v2: actually set ret = -1 on failure
v3: add a --feature option for suspend_seccomp (and make this patch 1,
    since the tests depend on it now)
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Andrew Vagin <avagin@odin.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>