selftests: bonding: fix incorrect mac address

selftests: bonding: fix incorrect mac address

The correct mac address for NS target 2001:db8::254 is 33:33:ff:00:02:54,
not 33:33:00:00:02:54. The same with client maddress.

Fixes: 86fb6173d11e ("selftests: bonding: add ns multicast group testing")
Acked-by: Jay Vosburgh <jv@jvosburgh.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250306023923.38777-3-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>