zdtm: don't execute ipc_namespace in userns (v2)

There is no permissions to set sysctl-s

v2: add the suid flag
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/ipc_namespace.desc

-{'flavor': 'ns uns'}
+{'flavor': 'ns', 'flags' : 'suid'}