Use obj_pos_of helper instead direct member access

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
socket: Fix __write_skb_queue early exit

Queues are sequential but we should not exit
that early otherwise we might skip writting
write queues.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
socket: Write packet entries for unix sockets only

TCP/IP streams are spliced in one bits stream.

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