[NETFILTER] IPV6: Fix dependencies.

Although the menu dependencies in net/ipv6/netfilter/Kconfig
guard the entries in that file from the Kconfig GUI, this does
not prevent them from being selected still via "make oldconfig"
when IPV6 etc. is disabled.

So add explicit dependencies.

Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/netfilter/Kconfig

@@ -7,7 +7,7 @@ menu "IPv6: Netfilter Configuration (EXPERIMENTAL)"
 
 config NF_CONNTRACK_IPV6
 	tristate "IPv6 connection tracking support (EXPERIMENTAL)"
-	depends on EXPERIMENTAL && NF_CONNTRACK
+	depends on INET && IPV6 && EXPERIMENTAL && NF_CONNTRACK
 	---help---
 	  Connection tracking keeps a record of what packets have passed
 	  through your machine, in order to figure out how they are related
@@ -21,6 +21,7 @@ config NF_CONNTRACK_IPV6
 
 config IP6_NF_QUEUE
 	tristate "IP6 Userspace queueing via NETLINK (OBSOLETE)"
+	depends on INET && IPV6 && NETFILTER && EXPERIMENTAL
 	---help---
 
 	  This option adds a queue handler to the kernel for IPv6
@@ -41,7 +42,7 @@ config IP6_NF_QUEUE
 
 config IP6_NF_IPTABLES
 	tristate "IP6 tables support (required for filtering)"
-	depends on NETFILTER_XTABLES
+	depends on INET && IPV6 && EXPERIMENTAL && NETFILTER_XTABLES
 	help
 	  ip6tables is a general, extensible packet identification framework.
 	  Currently only the packet filtering and packet mangling subsystem