media: s2255: 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: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Bhumika Goyal <bhumirks@gmail.com>
Cc: Mike Isely <isely@pobox.com>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/s2255/s2255drv.c

@@ -485,9 +485,10 @@ static void s2255_reset_dsppower(struct s2255_dev *dev)
 
 /* kickstarts the firmware loading. from probe
  */
-static void s2255_timer(unsigned long user_data)
+static void s2255_timer(struct timer_list *t)
 {
-	struct s2255_fw *data = (struct s2255_fw *)user_data;
+	struct s2255_dev *dev = from_timer(dev, t, timer);
+	struct s2255_fw *data = dev->fw_data;
 	if (usb_submit_urb(data->fw_urb, GFP_ATOMIC) < 0) {
 		pr_err("s2255: can't submit urb\n");
 		atomic_set(&data->fw_state, S2255_FW_FAILED);
@@ -2283,7 +2284,7 @@ static int s2255_probe(struct usb_interface *interface,
 		dev_err(&interface->dev, "Could not find bulk-in endpoint\n");
 		goto errorEP;
 	}
-	setup_timer(&dev->timer, s2255_timer, (unsigned long)dev->fw_data);
+	timer_setup(&dev->timer, s2255_timer, 0);
 	init_waitqueue_head(&dev->fw_data->wait_fw);
 	for (i = 0; i < MAX_CHANNELS; i++) {
 		struct s2255_vc *vc = &dev->vc[i];