eth: niu: fix calling napi_enable() in atomic context

napi_enable() may sleep now, take netdev_lock() before np->lock.

Fixes: 413f0271 ("net: protect NAPI enablement with netdev_lock()")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/dcfd56bc-de32-4b11-9e19-d8bd1543745d@stanley.mountain


Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250124031841.1179756-6-kuba@kernel.org


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