[IPv6] route: Simplify ip6_del_rt()

Provide a simple ip6_del_rt() for the majority of users and
an alternative for the exception via netlink. Avoids code
obfuscation.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f1ede90..27f2e33 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -736,7 +736,7 @@
 
 		if (rt && ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0)) {
 			if (onlink == 0) {
-				ip6_del_rt(rt, NULL, NULL, NULL);
+				ip6_del_rt(rt);
 				rt = NULL;
 			} else if (!(rt->rt6i_flags & RTF_EXPIRES)) {
 				rt->rt6i_expires = expires;
@@ -1662,7 +1662,7 @@
 		if (rt && ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0)) {
 			if (rt->rt6i_flags&RTF_EXPIRES) {
 				if (valid_lft == 0) {
-					ip6_del_rt(rt, NULL, NULL, NULL);
+					ip6_del_rt(rt);
 					rt = NULL;
 				} else {
 					rt->rt6i_expires = jiffies + rt_expires;
@@ -3557,7 +3557,7 @@
 			addrconf_leave_anycast(ifp);
 		addrconf_leave_solict(ifp->idev, &ifp->addr);
 		dst_hold(&ifp->rt->u.dst);
-		if (ip6_del_rt(ifp->rt, NULL, NULL, NULL))
+		if (ip6_del_rt(ifp->rt))
 			dst_free(&ifp->rt->u.dst);
 		break;
 	}