Linux 3.7: putname is no longer exported

Linux 3.7: putname is no longer exported

putname is unexported in kernel 3.7.  Add a compatibility inline
afs_putname function and open code it if necessary.

Reviewed-on: http://gerrit.openafs.org/8237
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
(cherry picked from commit fa3116567e2998af73eb116751032713850c9459)

Change-Id: Icf0e249f87bfe80a262e5599ab9958355ed9a90f
Reviewed-on: http://gerrit.openafs.org/8336
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>