Input: hp_sdc - use del_timer_sync() in exit path

Make sure that no callback is running before we teardown the module.

Signed-off-by: Thomas Gleixner <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/serio/hp_sdc.c

···
 	free_irq(hp_sdc.irq, &hp_sdc);
 	write_unlock_irq(&hp_sdc.lock);
 
-	del_timer(&hp_sdc.kicker);
+	del_timer_sync(&hp_sdc.kicker);
 
 	tasklet_kill(&hp_sdc.task);