The iptable processing was not handled in remote dataplane, and was
directly processed by the thread in charge of zapi calls. Now that call
can be handled in the zebra_dplane separate thread. once a
zebra_dplane_ctx is allocated for iptable handling, the hook call is
performed later. Subsequently, a return code may be triggered to zclient
interface if any problem occurs when calling the hook call.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>