staging: panel: replace del_timer by del_timer_sync

Author: Julia Lawall <Julia.Lawall@lip6.fr>

Use del_timer_sync to ensure that the timer is stopped on all CPUs before
the driver exists.

This change was suggested by Thomas Gleixner.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// 
@r@
declarer name module_exit;
identifier ex;
@@

module_exit(ex);

@@
identifier r.ex;
@@

ex(...) {
  <...
- del_timer
+ del_timer_sync
    (...)
  ...>
}
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/staging/panel/panel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 
diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
index 08f9a48..a53f94e 100644
--- a/drivers/staging/panel/panel.c
+++ b/drivers/staging/panel/panel.c
@@ -2298,7 +2298,7 @@ static void __exit panel_cleanup_module(void)
 	unregister_reboot_notifier(&panel_notifier);
 
 	if (scan_timer.function != NULL)
-		del_timer(&scan_timer);
+		del_timer_sync(&scan_timer);
 
 	if (pprt != NULL) {
 		if (keypad_enabled) {