Fix simple typos

This corrects some trivial errors in ARM docs and comments,

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/include/linux/timer.h b/include/linux/timer.h
index 9b9877f..ee5a09e 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -69,13 +69,13 @@
  * @timer: the timer to be added
  *
  * The kernel will do a ->function(->data) callback from the
- * timer interrupt at the ->expired point in the future. The
+ * timer interrupt at the ->expires point in the future. The
  * current time is 'jiffies'.
  *
- * The timer's ->expired, ->function (and if the handler uses it, ->data)
+ * The timer's ->expires, ->function (and if the handler uses it, ->data)
  * fields must be set prior calling this function.
  *
- * Timers with an ->expired field in the past will be executed in the next
+ * Timers with an ->expires field in the past will be executed in the next
  * timer tick.
  */
 static inline void add_timer(struct timer_list *timer)