mac80211: 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: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index e9c6aa3..db07e0d 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -1711,10 +1711,10 @@ void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
 	sdata_unlock(sdata);
 }
 
-static void ieee80211_ibss_timer(unsigned long data)
+static void ieee80211_ibss_timer(struct timer_list *t)
 {
 	struct ieee80211_sub_if_data *sdata =
-		(struct ieee80211_sub_if_data *) data;
+		from_timer(sdata, t, u.ibss.timer);
 
 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 }
@@ -1723,8 +1723,7 @@ void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 
-	setup_timer(&ifibss->timer, ieee80211_ibss_timer,
-		    (unsigned long) sdata);
+	timer_setup(&ifibss->timer, ieee80211_ibss_timer, 0);
 	INIT_LIST_HEAD(&ifibss->incomplete_stations);
 	spin_lock_init(&ifibss->incomplete_lock);
 	INIT_WORK(&ifibss->csa_connection_drop_work,