net: skbuff: hide nf_trace and ipvs_property

Accesses to nf_trace and ipvs_property are already wrapped
by ifdefs where necessary. Don't allocate the bits for those
fields at all if possible.
Acked-by: Florian Westphal <fw@strlen.de>
Acked-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -966,8 +966,12 @@ struct sk_buff {
 	__u8			ndisc_nodetype:2;
 #endif
 
+#if IS_ENABLED(CONFIG_IP_VS)
 	__u8			ipvs_property:1;
+#endif
+#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
 	__u8			nf_trace:1;
+#endif
 #ifdef CONFIG_NET_SWITCHDEV
 	__u8			offload_fwd_mark:1;
 	__u8			offload_l3_fwd_mark:1;