compat: backport netlink pid to portid rename

compat: backport netlink pid to portid rename

The patch:

commit 15e473046cb6e5d18a4d0057e61d76315230382b
Author: Eric W. Biederman <ebiederm@xmission.com>
Date:   Fri Sep 7 20:12:54 2012 +0000

    netlink: Rename pid to portid to avoid confusion

    It is a frequent mistake to confuse the netlink port identifier with a
    process identifier.  Try to reduce this confusion by renaming fields
    that hold port identifiers portid instead of pid.

    I have carefully avoided changing the structures exported to
    userspace to avoid changing the userspace API.

    I have successfully built an allyesconfig kernel with this change.

    Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
    Acked-by: Stephen Hemminger <shemminger@vyatta.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
Changed the struct members:

struct netlink_notify->pid    to
struct netlink_notify->portid

struct genl_info->snd_pid     to
struct genl_info->snd_portid

This adds helpers to help reduce the overhead cost to backport
this collateral evolution.

mcgrof@garbanzo ~/compat (git::master)$ time ckmake
Trying kernel 3.5.0-030500-generic [OK]
Trying kernel 3.4.4-030404-generic [OK]
Trying kernel 3.3.7-030307-generic [OK]
Trying kernel 3.2.2-030202-generic [OK]
Trying kernel 3.1.10-030110-generic [OK]
Trying kernel 3.0.18-030018-generic [OK]
Trying kernel 2.6.39-02063904-generic [OK]
Trying kernel 2.6.38-02063808-generic [OK]
Trying kernel 2.6.37-02063706-generic [OK]
Trying kernel 2.6.36-02063604-generic [OK]
Trying kernel 2.6.35-02063512-generic [OK]
Trying kernel 2.6.34-02063410-generic [OK]
Trying kernel 2.6.33-02063305-generic [OK]
Trying kernel 2.6.32-02063255-generic [OK]
Trying kernel 2.6.31-02063113-generic [OK]
Trying kernel 2.6.30-02063010-generic [OK]
Trying kernel 2.6.29-02062906-generic [OK]
Trying kernel 2.6.28-02062810-generic [OK]
Trying kernel 2.6.27-020627-generic [OK]
Trying kernel 2.6.26-020626-generic [OK]
Trying kernel 2.6.25-020625-generic [OK]
Trying kernel 2.6.24-020624-generic [OK]

real    1m0.017s
user    3m12.748s
sys     0m30.274s

Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>