[NET] Don't use magic number for sysctl table definition.

Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>

include/linux/sysctl.h

@@ -398,6 +398,7 @@ enum
 	NET_IPV4_CONF_FORCE_IGMP_VERSION=17,
 	NET_IPV4_CONF_ARP_ANNOUNCE=18,
 	NET_IPV4_CONF_ARP_IGNORE=19,
+	__NET_IPV4_CONF_MAX
 };
 
 /* /proc/sys/net/ipv4/netfilter */
@@ -476,7 +477,8 @@ enum {
 	NET_IPV6_REGEN_MAX_RETRY=14,
 	NET_IPV6_MAX_DESYNC_FACTOR=15,
 	NET_IPV6_MAX_ADDRESSES=16,
-	NET_IPV6_FORCE_MLD_VERSION=17
+	NET_IPV6_FORCE_MLD_VERSION=17,
+	__NET_IPV6_MAX
 };
 
 /* /proc/sys/net/ipv6/icmp */

net/ipv4/devinet.c

@@ -1212,7 +1212,7 @@ int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
 
 static struct devinet_sysctl_table {
 	struct ctl_table_header *sysctl_header;
-	ctl_table		devinet_vars[20];
+	ctl_table		devinet_vars[__NET_IPV4_CONF_MAX];
 	ctl_table		devinet_dev[2];
 	ctl_table		devinet_conf_dir[2];
 	ctl_table		devinet_proto_dir[2];

net/ipv6/addrconf.c

@@ -3212,7 +3212,7 @@ static int addrconf_sysctl_forward_strategy(ctl_table *table,
 static struct addrconf_sysctl_table
 {
 	struct ctl_table_header *sysctl_header;
-	ctl_table addrconf_vars[18];
+	ctl_table addrconf_vars[__NET_IPV6_MAX];
 	ctl_table addrconf_dev[2];
 	ctl_table addrconf_conf_dir[2];
 	ctl_table addrconf_proto_dir[2];