Printing the addresses can help us identify the exact skb/sk
for those system in which it's not that easy to run BPF program.
As we can see, it already fetches those, then use it directly
and it will print like below:

...tcp_retransmit_skb: skbaddr=XXX skaddr=XXX family=AF_INET...
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>