net/mlx5: fix multi-process port ID

net/mlx5: fix multi-process port ID

The device port_id is used for inter-process communication and must
be the same both for primary and secondary process

This IPC port_id was configured with the invalid temporary value in
port spawn routine. This temporary value was used by the function
rte_eth_dev_get_port_by_name() to check whether the port exists.

This commit corrects the mp port_id with rte_eth_dev port_id.

Fixes: 2eb4d0107acc ("net/mlx5: refactor PCI probing on Linux")
Cc: stable@dpdk.org
Signed-off-by: Suanming Mou <suanmingm@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>