HID: usbhid: cancel timer for retry synchronously

This makes sure IO is never restarted while a reset is going on

In particular there seems to be no protection from hid_retry_timeout() calling
hid_start_in() which would start IO after hid_pre_reset() has already called
hid_cease_io() because that uses del_timer(), not del_timer_sync()

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index ad978f5..77e705c 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -1270,7 +1270,7 @@
 
 static void hid_cease_io(struct usbhid_device *usbhid)
 {
-	del_timer(&usbhid->io_retry);
+	del_timer_sync(&usbhid->io_retry);
 	usb_kill_urb(usbhid->urbin);
 	usb_kill_urb(usbhid->urbctrl);
 	usb_kill_urb(usbhid->urbout);