[IPV6]: Fix modular build with netfilter enabled.

Also, drop __exit marker from ipv6_netfilter_fini() as this
can be invoked from inet6_init() error handling paths.

Based upon a report from Stephen Hemminger.
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/Makefile

@@ -12,13 +12,14 @@ ipv6-objs :=	af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o sit.o \
 
 ipv6-$(CONFIG_XFRM) += xfrm6_policy.o xfrm6_state.o xfrm6_input.o \
 	xfrm6_output.o
+ipv6-$(CONFIG_NETFILTER) += netfilter.o
 ipv6-objs += $(ipv6-y)
 
 obj-$(CONFIG_INET6_AH) += ah6.o
 obj-$(CONFIG_INET6_ESP) += esp6.o
 obj-$(CONFIG_INET6_IPCOMP) += ipcomp6.o
 obj-$(CONFIG_INET6_TUNNEL) += xfrm6_tunnel.o 
-obj-$(CONFIG_NETFILTER)	+= netfilter.o netfilter/
+obj-$(CONFIG_NETFILTER)	+= netfilter/
 
 obj-$(CONFIG_IPV6_TUNNEL) += ip6_tunnel.o
 

net/ipv6/netfilter.c

@@ -90,7 +90,10 @@ int __init ipv6_netfilter_init(void)
 	return nf_register_queue_rerouter(PF_INET6, &ip6_reroute);
 }
 
-void __exit ipv6_netfilter_fini(void)
+/* This can be called from inet6_init() on errors, so it cannot
+ * be marked __exit. -DaveM
+ */
+void ipv6_netfilter_fini(void)
 {
 	nf_unregister_queue_rerouter(PF_INET6);
 }