tun_dst: Remove opts_size

opts_size is only written and never read. Following patch
removes this unused variable.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/dst_metadata.h

@@ -7,7 +7,6 @@
 
 struct metadata_dst {
 	struct dst_entry		dst;
-	size_t				opts_len;
 	union {
 		struct ip_tunnel_info	tun_info;
 	} u;

net/core/dst.c

@@ -378,7 +378,6 @@ static void __metadata_dst_init(struct metadata_dst *md_dst, u8 optslen)
 	dst->output = dst_md_discard_sk;
 
 	memset(dst + 1, 0, sizeof(*md_dst) + optslen - sizeof(*dst));
-	md_dst->opts_len = optslen;
 }
 
 struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags)