net/mlx5: E-Switch Make cleanup sequence mirror of init

Make cleanup sequence mirror of init sequence for cleaning up reps
and freeing vports.

Also when reps initialization fails, there is no need to perform reps
cleanup.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>