net: veth: Disable netpoll support

The current implementation of netpoll in veth devices leads to
suboptimal behavior, as it triggers warnings due to the invocation of
__netif_rx() within a softirq context. This is not compliant with
expected practices, as __netif_rx() has the following statement:

	lockdep_assert_once(hardirq_count() | softirq_count());

Given that veth devices typically do not benefit from the
functionalities provided by netpoll, Disable netpoll for veth
interfaces.

Signed-off-by: Breno Leitao <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: leitao

drivers/net/veth.c

@@ -1696,6 +1696,7 @@ static void veth_setup(struct net_device *dev)
 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
 	dev->priv_flags |= IFF_NO_QUEUE;
 	dev->priv_flags |= IFF_PHONY_HEADROOM;
+	dev->priv_flags |= IFF_DISABLE_NETPOLL;
 
 	dev->netdev_ops = &veth_netdev_ops;
 	dev->xdp_metadata_ops = &veth_xdp_metadata_ops;