net/mlx5e: Fix error path of updating netdev queues

Avoid division by zero in the error flow. In the driver TC number can be
either 1 or 8. When TC count is set to 1, driver zero netdev->num_tc.
Hence, need to convert it back from 0 to 1 in the error flow.

Fixes: fa374877 ("net/mlx5e: Handle errors from netif_set_real_num_{tx,rx}_queues")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>