netfilter: Build fixups - kuid/kguid changes & xt_socket_get/put_sk

Fix up build kuid/kguid build issues in netfilter code.

Also re-add the xt_socket_get/put_sk interfaces needed by xt_qtaguid.

Change-Id: I7027fb840e109785bddffe8ea717b8d018b26d82
Signed-off-by: John Stultz <john.stultz@linaro.org>
xt_qtaguid: Fix boot panic

We need the change below because of mainline commit 351638e7de (net: pass
info struct via netdevice notifier). Otherwise we panic.

Change-Id: I7daf7513a733933fdcbaeebea7f8191f8b6a0432
Signed-off-by: John Stultz <john.stultz@linaro.org>