netfilter: nfnetlink_queue: reject verdict request from different portid

commit 00a3101f561816e58de054a470484996f78eb5eb upstream.

Like NFQNL_MSG_VERDICT_BATCH do, we should also reject the verdict
request when the portid is not same with the initial portid(maybe
from another process).

Fixes: 97d32cf9440d ("netfilter: nfnetlink_queue: batch verdict support")
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>