net/mlx5e: Do not try enable RSS when resetting indir table

All calls to mlx5e_rx_res_rss_set_indir_uniform() occur while the RSS
state is inactive, i.e. the RQT is pointing to the drop RQ, not to the
channels' RQs.
It means that the "apply" part of the function is not called.
Remove this part from the function, and document the change. It will be
useful for next patches in the series, allows code simplifications when
multiple RSS contexts are introduced.

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>