Allow both indices and keys to exist for objects in pools. Previously you were limited to one or the other. This is required for later implementing rxe memory windows. Link: https://lore.kernel.org/r/20201216231550.27224-3-rpearson@hpe.com Signed-off-by: Bob Pearson <rpearson@hpe.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>