net/mlx5e: Don't flush SQ on error

We are doing SQ descriptors cleanup in driver.

Fixes: 6e8dd6d6 ("net/mlx5e: Don't wait for SQ completions on close")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>