net/mlx5: Fix the order of fc_stats cleanup

Previously, mlx5_cleanup_fc_stats() would cleanup the flow counter
pool beofre releasing all the counters to it, which would result in
flow counter bulks not getting freed. Resolve this by changing the
order in which elements of fc_stats are cleaned up, so that the flow
counter pool is cleaned up after all the counters are released.

Also move cleanup actions for freeing the bulk query memory and
destroying the idr to the end of mlx5_cleanup_fc_stats().

Signed-off-by: Gavi Teitz <gavi@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>