skbuff: Release nfct refcount on napi stolen or re-used skbs

stable inclusion
from stable-5.10.54
commit 570341f10eccfe5c339363544a0339a8550944b7
bugzilla: 175586 https://gitee.com/openeuler/kernel/issues/I4DVDU

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=570341f10eccfe5c339363544a0339a8550944b7



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commit 8550ff8d upstream.

When multiple SKBs are merged to a new skb under napi GRO,
or SKB is re-used by napi, if nfct was set for them in the
driver, it will not be released while freeing their stolen
head state or on re-use.

Release nfct on napi's stolen or re-used SKBs, and
in gro_list_prepare, check conntrack metadata diff.

Fixes: 5c6b9460 ("net/mlx5e: CT: Handle misses after executing CT action")
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>