Linux: Rework handling of names in the lookup functions

Linux: Rework handling of names in the lookup functions

Rework the name lookup functions in the kernel to deal more cleanly
with the change of API for kernel 3.7

Reviewed-on: http://gerrit.openafs.org/8278
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
(cherry picked from commit eca04c7e52d1e777cde423cdf673d7bf579c342b)

Change-Id: I967c80fac754fbee1836b84dfb50dd5fdcba35f0
Reviewed-on: http://gerrit.openafs.org/8338
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>