net/mlx5e: TC, fix cloned flow attribute

Currently the cloned flow attr resets the original tc action cookies
count.
Fix that by resetting the cloned flow attribute.

Fixes: cca7eac1 ("net/mlx5e: TC, store tc action cookies per attr")
Signed-off-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>