LU-451 Workaround for lockd (nfsv3) locking

It seems that lockd works in a different way lock-wise compared
to everybody else. They actually don't use lock owner to determine
conflicts and install their own owner compare that compares specially
crafted pids (duh!).
As a workaround if a custom owner compare is detected, assign pid to
owner field (not intersecting with kernel pointer space anyway).
svclock is the only place using custom owner compare function ATM.

Change-Id: Ia89e2327705f2afbe200fdbadd0f86038fda936d
Signed-off-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/1174
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Johann Lombardi <johann@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>