Doxygen typo fix.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@14612 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/sched.h

@@ -72,7 +72,7 @@ typedef int (*ast_sched_cb)(void *data);
 extern int ast_sched_add(struct sched_context *con, int when, ast_sched_cb callback, void *data);
 
 /*!Adds a scheduled event with rescheduling support
- * \param con Scehduler context to add
+ * \param con Scheduler context to add
  * \param when how many milliseconds to wait for event to occur
  * \param callback function to call when the amount of time expires
  * \param data data to pass to the callback