Backport of:

----------------------------------------------------------
revno: 2617.23.19
committer: Konstantin Osipov <kostja@sun.com>
branch nick: mysql-6.0-runtime
timestamp: Tue 2009-03-03 01:20:44 +0300
message:
  Metadata locking: realign comments. No semantical changes,
  only enforce a bit of the coding style.
This is a review fix for WL#4284 "Transactional DDL locking".

sql/mdl.cc:
  Realign doxygen comments.
sql/mdl.h:
  Realign doxygen comments.

sql/mdl.cc

@@ -48,7 +48,7 @@ struct MDL_LOCK
   MDL_KEY key;
   /** List of granted tickets for this lock. */
   Ticket_list granted;
-  /*
+  /**
     There can be several upgraders and active exclusive
     belonging to the same context.
   */
@@ -298,7 +298,7 @@ void mdl_request_init(MDL_LOCK_REQUEST *lock_req, unsigned char type,
 
   @note The allocated lock request will have MDL_SHARED type.
 
-   @retval 0      Error
+  @retval 0      Error if out of memory
   @retval non-0  Pointer to an object representing a lock request
 */
 
@@ -1399,7 +1399,6 @@ void mdl_ticket_release_all(MDL_CONTEXT *context)
 
   @param context   Context containing lock in question
   @param ticket    Lock to be released
-
 */
 
 void mdl_ticket_release(MDL_CONTEXT *context, MDL_LOCK_TICKET *ticket)