net/mlx4_en: Remove ethtool flow steering rules before releasing QPs

Fix the ethtool flow steering rules cleanup to be carried out before
releasing the RX QPs.

Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>