staging: lustre: o2iblnd: remove last of kiblnd_tunables_fini

staging: lustre: o2iblnd: remove last of kiblnd_tunables_fini

The function kibnd_tunables_fini() no longer exist. Remove
it from o2iblnd.h

Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7101
Reviewed-on: http://review.whamcloud.com/16367
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Olaf Weber <olaf@sgi.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>