ipv6: Kill rt6i_dev and rt6i_expires defines.

It just obscures that the netdevice pointer and the expires value are
implemented in the dst_entry sub-object of the ipv6 route.

And it makes grepping for dst_entry member uses much harder too.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 85421cc..647e6cb 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -797,7 +797,7 @@
 				ip6_del_rt(rt);
 				rt = NULL;
 			} else if (!(rt->rt6i_flags & RTF_EXPIRES)) {
-				rt->rt6i_expires = expires;
+				rt->dst.expires = expires;
 				rt->rt6i_flags |= RTF_EXPIRES;
 			}
 		}
@@ -1723,7 +1723,7 @@
 	if (!fn)
 		goto out;
 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
-		if (rt->rt6i_dev->ifindex != dev->ifindex)
+		if (rt->dst.dev->ifindex != dev->ifindex)
 			continue;
 		if ((rt->rt6i_flags & flags) != flags)
 			continue;
@@ -1881,11 +1881,11 @@
 				rt = NULL;
 			} else if (addrconf_finite_timeout(rt_expires)) {
 				/* not infinity */
-				rt->rt6i_expires = jiffies + rt_expires;
+				rt->dst.expires = jiffies + rt_expires;
 				rt->rt6i_flags |= RTF_EXPIRES;
 			} else {
 				rt->rt6i_flags &= ~RTF_EXPIRES;
-				rt->rt6i_expires = 0;
+				rt->dst.expires = 0;
 			}
 		} else if (valid_lft) {
 			clock_t expires = 0;