tests:ethernets: avoid flaky test_ip6_eui64 results, when statefull D…

…HCPv6 is quicker than stateless EUI-64 address generation

tests/integration/ethernets.py

@@ -250,9 +250,9 @@ def test_ip6_eui64(self):
       dhcp6: yes
       accept-ra: yes
       ipv6-address-generation: eui64''' % {'r': self.backend, 'ec': self.dev_e_client})
-        self.generate_and_settle([self.state_dhcp6(self.dev_e_client)])
         # Compare to EUI-64 address, to make sure it matches the one generated.
         eui_addr = mac_to_eui64(self.dev_e_client_mac)
+        self.generate_and_settle([self.state(self.dev_e_client, eui_addr.compressed)])
         self.assert_iface_up(self.dev_e_client, [f'inet6 {eui_addr.compressed}/64'])
 
     def test_link_local_all(self):