[IPV6]: remove more unused IPV6_AUTHHDR things.

Remove two more unused IPV6_AUTHHDR option things,
which I failed to remove them last time,
plus, mark IPV6_AUTHHDR obsolete.

Signed-off-by: YOSHIFUJI Hideaki <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/in6.h

···
 #define IPV6_CHECKSUM		7
 #define IPV6_HOPLIMIT		8
 #define IPV6_NEXTHOP		9
-#define IPV6_AUTHHDR		10
+#define IPV6_AUTHHDR		10	/* obsolete */
 #define IPV6_FLOWINFO		11
 
 #define IPV6_UNICAST_HOPS	16

include/net/ipv6.h

···
 	struct ipv6_opt_hdr	*hopopt;
 	struct ipv6_opt_hdr	*dst0opt;
 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
-	struct ipv6_opt_hdr	*auth;
 	struct ipv6_opt_hdr	*dst1opt;
 
 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */

net/ipv6/ip6_flowlabel.c

···
 		opt_space->opt_nflen = 0;
 	}
 	opt_space->dst1opt = fopt->dst1opt;
-	opt_space->auth = fopt->auth;
 	opt_space->opt_flen = fopt->opt_flen;
 	return opt_space;
 }