addr_adv PM list old IP addresses

[matttbe]

Describe the bug With mptcpd 0.10, I can see some IPs that are no longer assigned to any interfaces on my laptop, e.g.

$ ip mptcp endpoint
fe80::(...) id 3 dev if5
10.124.(...) id 4 dev if5
10.124.(...) id 6 dev if6
fe80::(...) id 15 dev if11
fe80::(...) id 24 dev wlan0
10.44.(...) id 25 subflow dev wlan0

To Reproduce I connected to different networks with my laptop, switching to sleep mode in between.

Expected behavior Only endpoints that are still attached to an interface and its IP.

Desktop (please complete the following information):

• Linux Kernel: 5.19
• Compiler: Debian/Ubuntu packages

Additional context /