LU-6142 lustre: all rhashtable_params should be static.

LU-6142 lustre: all rhashtable_params should be static.

pools_hash_params and nid_hash_params are only used in the file where
they are declared - which is best for rhashtable params.
However they are not declared 'static', and one is even EXPORTed.

Change them both to 'static' and remove the EXPORT.

Test-Parameters: trivial
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: Ib71f8a7c3bfa38fa54b3653d51786a3d8da6117f
Reviewed-on: https://review.whamcloud.com/39730
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>