net: lantiq_etop: don't free skb when returning NETDEV_TX_BUSY

stable inclusion
from stable-v5.10.153
commit aab883bd60bcd682b1ccd0bf94989fbabf2f9ad5
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I64YCA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=aab883bd60bcd682b1ccd0bf94989fbabf2f9ad5



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[ Upstream commit 9c1eaa27 ]

The ndo_start_xmit() method must not free skb when returning
NETDEV_TX_BUSY, since caller is going to requeue freed skb.

Fixes: 504d4721 ("MIPS: Lantiq: Add ethernet driver")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lipeng Sang <sanglipeng1@jd.com>