eth: sungem: remove .ndo_poll_controller to avoid deadlocks

mainline inclusion
from mainline-v6.10-rc1
commit ac0a230f719b02432d8c7eba7615ebd691da86f4
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6S6S
CVE: CVE-2024-38597

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ac0a230f719b02432d8c7eba7615ebd691da86f4



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Erhard reports netpoll warnings from sungem:

  netpoll_send_skb_on_dev(): eth0 enabled interrupts in poll (gem_start_xmit+0x0/0x398)
  WARNING: CPU: 1 PID: 1 at net/core/netpoll.c:370 netpoll_send_skb+0x1fc/0x20c

gem_poll_controller() disables interrupts, which may sleep.
We can't sleep in netpoll, it has interrupts disabled completely.
Strangely, gem_poll_controller() doesn't even poll the completions,
and instead acts as if an interrupt has fired so it just schedules
NAPI and exits. None of this has been necessary for years, since
netpoll invokes NAPI directly.

Fixes: fe09bb61 ("sungem: Spring cleaning and GRO support")
Reported-and-tested-by: Erhard Furtner <erhard_f@mailbox.org>
Link: https://lore.kernel.org/all/20240428125306.2c3080ef@legion


Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240508134504.3560956-1-kuba@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Conflicts:
	drivers/net/ethernet/sun/sungem.c
[Adjust context conflicts]
Signed-off-by: Liu Chuang <liuchuang40@huawei.com>