A blue flame register is comprised of two buffers of equal size.

Fixes: 5fe9dec0 ("IB/mlx5: Use blue flame register allocator in mlx5_ib")
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NNoa Osherovich <noaos@mellanox.com>
Reviewed-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>