net/bonding: fix MAC address when switching active port

net/bonding: fix MAC address when switching active port

Currently, based on a active-backup bond device, when the link status of
the primary port changes from up to down, one slave port changes to the
primary port, but the new primary port's MAC address cannot change to
the bond device's MAC address. And we can't continue receive packets
whose destination MAC addresses are the same as the bond devices's MAC
address.

The current bonding PMD driver call mac_address_slaves_update function
to modify the MAC address of all slaves devices: the primary port using
bond device's MAC address, and other slaves devices using the respective
MAC address. We found that one error using primary_port instead of
current_primary_port in mac_address_slaves_update function.

On the other hand, The current bonding PMD driver sets slave devices's
MAC address according to the variable named current_primary_port. The
variable named current_primary_port changes in the following scenario:
1. Add the slave devices to bond, the first slave port will be regarded
   as the current_primary_port. If changing the order of adding the
   slave devices, the value of the variable named current_primary_port
   will be different.
2. The upper application specifies primary_port via calling the
   rte_eth_bond_primary_set API function.
3. Delete the primary slave device.
4. The link status of the primary port changes from up to down.

We have tested the above 4 cases and found that there are problems that
the new primary port's MAC address didn't change to the bond device's
MAC address when running case 3 and 4. When current_primary_port
changes, the new primary port's MAC address should change at the same
time. We also need to call mac_address_slaves_update function to update
MAC addresses in case
3 and 4.

Bugzilla ID: 256
Fixes: 2efb58cbab6e ("bond: new link bonding library")
Cc: stable@dpdk.org
Signed-off-by: Chunsong Feng <fengchunsong@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>