macvlan: implement .parse_protocol hook function in macvlan_hard_header_ops

The .parse_protocol hook function in the macvlan_header_ops structure is
not implemented. As a result, when the AF_PACKET family is used to send
packets, skb->protocol will be set to 0.
Macvlan is a device of type ARPHRD_ETHER (ether_setup). Therefore, use
eth_header_parse_protocol function to obtain the protocol.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20231202130658.2266526-1-shaozhengchao@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/macvlan.c

@@ -609,6 +609,7 @@ static const struct header_ops macvlan_hard_header_ops = {
 	.parse		= eth_header_parse,
 	.cache		= eth_header_cache,
 	.cache_update	= eth_header_cache_update,
+	.parse_protocol	= eth_header_parse_protocol,
 };
 
 static int macvlan_open(struct net_device *dev)