netfilter: nf_queue: fix NF_STOLEN skb leak

commit 3bc38712 (handle NF_STOP and unknown verdicts in
nf_reinject) was a partial fix to packet leaks.

If user asks NF_STOLEN status, we must free the skb as well.

Reported-by: Afi Gjermund <afigjermund@gmail.com>
Signed-off-by: Eric DUmazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>