net: avoid quadratic behavior in netdev_wait_allrefs_any()

net-next inclusion
from net-next-v5.17-rc5
commit 86213f80
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4VZN0?from=project-issue

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=86213f80da1b1d007721cc22e04b5f5d0da33127



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If the list of devices has N elements, netdev_wait_allrefs_any()
is called N times, and linkwatch_forget_dev() is called N*(N-1)/2 times.

Fix this by calling linkwatch_forget_dev() only once per device.

Fixes: faab39f6 ("net: allow out-of-order netdev unregistration")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220218065430.2613262-1-eric.dumazet@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>