inet: frags: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Stefan Schmidt <stefan@osg.samsung.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Florian Westphal <fw@strlen.de>
Cc: linux-wpan@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
Cc: coreteam@netfilter.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Stefan Schmidt <stefan@osg.samsung.com> # for ieee802154
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/reassembly.c

@@ -170,12 +170,13 @@ out:
 }
 EXPORT_SYMBOL(ip6_expire_frag_queue);
 
-static void ip6_frag_expire(unsigned long data)
+static void ip6_frag_expire(struct timer_list *t)
 {
+	struct inet_frag_queue *frag = from_timer(frag, t, timer);
 	struct frag_queue *fq;
 	struct net *net;
 
-	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
+	fq = container_of(frag, struct frag_queue, q);
 	net = container_of(fq->q.net, struct net, ipv6.frags);
 
 	ip6_expire_frag_queue(net, fq, &ip6_frags);