netfilter: conntrack: include ecache dying list in dumps

The new pernet dying list includes conntrack entries that await
delivery of the 'destroy' event via ctnetlink.

The old percpu dying list will be removed soon.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>