Linux: 2.6.39: replace path_lookup with kern_path

Linux: 2.6.39: replace path_lookup with kern_path

path_lookup is no longer available, use kern_path instead.

Reviewed-on: http://gerrit.openafs.org/4360
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 7d162266c4958b22cc45d65e3f204a96c218e5f6)

Change-Id: I1c2aba273d1d597346ecb92f75caed6b6d624454
Reviewed-on: http://gerrit.openafs.org/4371
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>