ipv6: update ip6_rt_last_gc every time GC is run

As pointed out by Eric Dumazet, net->ipv6.ip6_rt_last_gc should
hold the last time garbage collector was run so that we should
update it whenever fib6_run_gc() calls fib6_clean_all(), not only
if we got there from ip6_dst_gc().

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 824c424..b70f8979 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1311,7 +1311,6 @@
 
 static int ip6_dst_gc(struct dst_ops *ops)
 {
-	unsigned long now = jiffies;
 	struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
 	int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
 	int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
@@ -1321,13 +1320,12 @@
 	int entries;
 
 	entries = dst_entries_get_fast(ops);
-	if (time_after(rt_last_gc + rt_min_interval, now) &&
+	if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
 	    entries <= rt_max_size)
 		goto out;
 
 	net->ipv6.ip6_rt_gc_expire++;
 	fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, entries > rt_max_size);
-	net->ipv6.ip6_rt_last_gc = now;
 	entries = dst_entries_get_slow(ops);
 	if (entries < ops->gc_thresh)
 		net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;