netlink: Document all fields of 'struct nl_info'

Some fields were not documented. Add documentation.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netlink.h

@@ -378,7 +378,9 @@ struct nla_policy {
 /**
  * struct nl_info - netlink source information
  * @nlh: Netlink message header of original request
+ * @nl_net: Network namespace
  * @portid: Netlink PORTID of requesting application
+ * @skip_notify: Skip netlink notifications to user space
  */
 struct nl_info {
 	struct nlmsghdr		*nlh;