bridge: fix IPV6=n build

Fix bridge netfilter code so that it uses CONFIG_IPV6 as needed:

net/built-in.o: In function `ebt_filter_ip6':
ebt_ip6.c:(.text+0x87c37): undefined reference to `ipv6_skip_exthdr'
net/built-in.o: In function `ebt_log_packet':
ebt_log.c:(.text+0x88dee): undefined reference to `ipv6_skip_exthdr'
make[1]: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/netfilter/Kconfig

@@ -85,7 +85,7 @@ config BRIDGE_EBT_IP
 
 config BRIDGE_EBT_IP6
 	tristate "ebt: IP6 filter support"
-	depends on BRIDGE_NF_EBTABLES
+	depends on BRIDGE_NF_EBTABLES && IPV6
 	help
 	  This option adds the IP6 match, which allows basic IPV6 header field
 	  filtering.

net/bridge/netfilter/Makefile

@@ -14,7 +14,7 @@ obj-$(CONFIG_BRIDGE_EBT_802_3) += ebt_802_3.o
 obj-$(CONFIG_BRIDGE_EBT_AMONG) += ebt_among.o
 obj-$(CONFIG_BRIDGE_EBT_ARP) += ebt_arp.o
 obj-$(CONFIG_BRIDGE_EBT_IP) += ebt_ip.o
-obj-$(CONFIG_BRIDGE_EBT_IP) += ebt_ip6.o
+obj-$(CONFIG_BRIDGE_EBT_IP6) += ebt_ip6.o
 obj-$(CONFIG_BRIDGE_EBT_LIMIT) += ebt_limit.o
 obj-$(CONFIG_BRIDGE_EBT_MARK) += ebt_mark_m.o
 obj-$(CONFIG_BRIDGE_EBT_PKTTYPE) += ebt_pkttype.o

net/bridge/netfilter/ebt_log.c

@@ -123,6 +123,7 @@ ebt_log_packet(unsigned int pf, unsigned int hooknum,
 		goto out;
 	}
 
+#if defined(CONFIG_BRIDGE_EBT_IP6) || defined(CONFIG_BRIDGE_EBT_IP6_MODULE)
 	if ((bitmask & EBT_LOG_IP6) && eth_hdr(skb)->h_proto ==
 	   htons(ETH_P_IPV6)) {
 		const struct ipv6hdr *ih;
@@ -146,6 +147,7 @@ ebt_log_packet(unsigned int pf, unsigned int hooknum,
 		print_ports(skb, nexthdr, offset_ph);
 		goto out;
 	}
+#endif
 
 	if ((bitmask & EBT_LOG_ARP) &&
 	    ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) ||