net/mlx5e: Tx, Fix assumption of single WQEBB of NOP in cleanup flow

Cited patch removed the assumption only in datapath.
Here we remove it also form control/cleanup flow.

Fixes: 9ab02337

 ("net/mlx5e: Tx, Don't implicitly assume SKB-less wqe has one WQEBB")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>