net/mlx5: fix leak when configured repeatedly

net/mlx5: fix leak when configured repeatedly

Currently, configuring a mlx device, it will allocate its
own process private in mlx5_proc_priv_init() and only frees
it when closing the device. This will lead to a memory leak,
when a device is configured repeatedly.

For example:
for(...)
do
    rte_eth_dev_configure
    rte_eth_rx_queue_setup
    rte_eth_tx_queue_setup
    rte_eth_dev_start
    rte_eth_dev_stop
done

Fixes: 120dc4a7dcd3 ("net/mlx5: remove device register remap")
Cc: stable@dpdk.org
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>