net/mlx5e: Remove redundant checks in set_ringparam

Since the checks are done in upper layer ethtool code,
checks in driver are not needed any more.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>