lantiq: net: fix duplicated skb in rx descriptor ring

stable inclusion
from stable-5.10.46
commit 70c8418469fb22a679fe5015ebe60fe15011ea43
bugzilla: 168323
CVE: NA

--------------------------------

[ Upstream commit 7ea6cd16 ]

The previous commit didn't fix the bug properly. By mistake, it replaces
the pointer of the next skb in the descriptor ring instead of the current
one. As a result, the two descriptors are assigned the same SKB. The error
is seen during the iperf test when skb_put tries to insert a second packet
and exceeds the available buffer.

Fixes: c7718ee9 ("net: lantiq: fix memory corruption in RX ring ")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>