ipv6: addrconf.c: remove unnecessary "if"

the value of err is always negative if it goes to errout, so we don't need to
check the value of err.

Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6fca01f..408cac4a 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -534,8 +534,7 @@
 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_NETCONF, NULL, GFP_ATOMIC);
 	return;
 errout:
-	if (err < 0)
-		rtnl_set_sk_err(net, RTNLGRP_IPV6_NETCONF, err);
+	rtnl_set_sk_err(net, RTNLGRP_IPV6_NETCONF, err);
 }
 
 static const struct nla_policy devconf_ipv6_policy[NETCONFA_MAX+1] = {