Linux: 2.6.39: deal with BKL removal

Linux: 2.6.39: deal with BKL removal

For 2.6 kernels the OpenAFS code is already BKL free, but the
corresponding header file smp_lock.h is still included in various
places.  This header no longer exists, so remove all occurrences
outside of LINUX24.

Reviewed-on: http://gerrit.openafs.org/4361
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 9376293634393597ac7db88593100937621f6c3f)

Change-Id: I8e7e244b2e45a7a3af0505531757b8a54a0b3d29
Reviewed-on: http://gerrit.openafs.org/4370
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>