selftests: bonding: add macvlan over bond testing

Add a macvlan over bonding test with mode active-backup, balance-tlb
and balance-alb.

]# ./bond_macvlan.sh
TEST: active-backup: IPv4: client->server [ OK ]
TEST: active-backup: IPv6: client->server [ OK ]
TEST: active-backup: IPv4: client->macvlan_1 [ OK ]
TEST: active-backup: IPv6: client->macvlan_1 [ OK ]
TEST: active-backup: IPv4: client->macvlan_2 [ OK ]
TEST: active-backup: IPv6: client->macvlan_2 [ OK ]
TEST: active-backup: IPv4: macvlan_1->macvlan_2 [ OK ]
TEST: active-backup: IPv6: macvlan_1->macvlan_2 [ OK ]
TEST: active-backup: IPv4: server->client [ OK ]
TEST: active-backup: IPv6: server->client [ OK ]
TEST: active-backup: IPv4: macvlan_1->client [ OK ]
TEST: active-backup: IPv6: macvlan_1->client [ OK ]
TEST: active-backup: IPv4: macvlan_2->client [ OK ]
TEST: active-backup: IPv6: macvlan_2->client [ OK ]
TEST: active-backup: IPv4: macvlan_2->macvlan_2 [ OK ]
TEST: active-backup: IPv6: macvlan_2->macvlan_2 [ OK ]
[...]
TEST: balance-alb: IPv4: client->server [ OK ]
TEST: balance-alb: IPv6: client->server [ OK ]
TEST: balance-alb: IPv4: client->macvlan_1 [ OK ]
TEST: balance-alb: IPv6: client->macvlan_1 [ OK ]
TEST: balance-alb: IPv4: client->macvlan_2 [ OK ]
TEST: balance-alb: IPv6: client->macvlan_2 [ OK ]
TEST: balance-alb: IPv4: macvlan_1->macvlan_2 [ OK ]
TEST: balance-alb: IPv6: macvlan_1->macvlan_2 [ OK ]
TEST: balance-alb: IPv4: server->client [ OK ]
TEST: balance-alb: IPv6: server->client [ OK ]
TEST: balance-alb: IPv4: macvlan_1->client [ OK ]
TEST: balance-alb: IPv6: macvlan_1->client [ OK ]
TEST: balance-alb: IPv4: macvlan_2->client [ OK ]
TEST: balance-alb: IPv6: macvlan_2->client [ OK ]
TEST: balance-alb: IPv4: macvlan_2->macvlan_2 [ OK ]
TEST: balance-alb: IPv6: macvlan_2->macvlan_2 [ OK ]

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>