net/mlx4_en: IRQ affinity hint is not cleared on port down

Need to remove affinity hint at mlx4_en_deactivate_cq() and not at
mlx4_en_destroy_cq() - since affinity_mask might be free'd while still
being used by procfs.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>