Linux: fix afs_putname wrapper for pre-3.7 kernels

Linux: fix afs_putname wrapper for pre-3.7 kernels

Make the compatibility function use the right type for pre-3.7
kernels.

Reviewed-on: http://gerrit.openafs.org/8276
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
(cherry picked from commit 115850076c09625e37d75da6dc29a68b0a2d638e)

Change-Id: I820340058a6cdecbd438fdc13ed3d54a439340e0
Reviewed-on: http://gerrit.openafs.org/8337
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>