make failed in Kernel 5.2 and later

[nokia-t1zhou]

in the kernel version 5.2.x and later, the struct genl_ops delete filed "policy", this will cause make failed.
the new definition is:

/**
 * struct genl_ops - generic netlink operations
 * @cmd: command identifier
 * @internal_flags: flags used by the family
 * @flags: flags
 * @doit: standard command callback
 * @start: start callback for dumps
 * @dumpit: callback for dumpers
 * @done: completion callback for dumps
 */
struct genl_ops {
	int		       (*doit)(struct sk_buff *skb,
				       struct genl_info *info);
	int		       (*start)(struct netlink_callback *cb);
	int		       (*dumpit)(struct sk_buff *skb,
					 struct netlink_callback *cb);
	int		       (*done)(struct netlink_callback *cb);
	u8			cmd;
	u8			internal_flags;
	u8			flags;
	u8			validate;
};

[vmag]

We have PR for this: #9