[NETNS][FRAGS]: Make thresholds work in namespaces.

This is the same as with the timeout variable.

Currently, after exceeding the high threshold _all_
the fragments are evicted, but it will be fixed in
later patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 9da9679..5ab399c 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -153,7 +153,7 @@
 	struct inet_frag_queue *q;
 	int work, evicted = 0;
 
-	work = atomic_read(&nf->mem) - f->ctl->low_thresh;
+	work = atomic_read(&nf->mem) - nf->low_thresh;
 	while (work > 0) {
 		read_lock(&f->lock);
 		if (list_empty(&f->lru_list)) {