net/mlx5: Restore missing scheduling node cleanup on vport enable failure

net/mlx5: Restore missing scheduling node cleanup on vport enable failure

Restore the __esw_qos_free_node() call removed by the offending commit.

Fixes: 97733d1e00a0 ("net/mlx5: Add traffic class scheduling support for vport QoS")
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Link: https://patch.msgid.link/20250820133209.389065-7-mbloch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>