[IPV6] SYSCTL: Fix possible memory leakage in error path.

In error path, we do need to free memory just allocated.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/sysctl_net_ipv6.c

@@ -101,9 +101,6 @@ static int ipv6_sysctl_net_init(struct net *net)
 
 	net->ipv6.sysctl.table = register_net_sysctl_table(net, net_ipv6_ctl_path,
 							   ipv6_table);
-	if (!net->ipv6.sysctl.table)
-		return -ENOMEM;
-
 	if (!net->ipv6.sysctl.table)
 		goto out_ipv6_icmp_table;