staging: lustre: remove unused hash tables.

exp_lock_hash and exp_flock_hash are unused in
the client, so remove all references.

Also remove unused hashtable size definitions.

Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>