REORGANIZE PARTITION

There were several problems which lead to this this,
all related to bad error handling.

1) There was several bugs preventing the ddl-log to be used for
   cleaning up created files on error.

2) The error handling after the copy partition rows did not close
   and unlock the tables, resulting in deletion of partitions
   which were in use, which lead InnoDB to put the partition to
   drop in a background queue.

sql/ha_partition.cc:
  Bug#47343: InnoDB fails to clean-up after lock wait timeout on
             REORGANIZE PARTITION
  
  Better error handling, if partition has been created/opened/locked
  then make sure it is unlocked and closed before returning error.
  The delete of the newly created partition is handled by the ddl-log.
sql/sql_parse.cc:
  Bug#47343: InnoDB fails to clean-up after lock wait timeout on
             REORGANIZE PARTITION
  
  Fix a bug found when experimenting, thd could really be NULL here,
  as mentioned in the function header.
sql/sql_partition.cc:
  Bug#47343: InnoDB fails to clean-up after lock wait timeout on
             REORGANIZE PARTITION
  
  Used the correct .frm shadow name to put into the ddl-log.
  Really use the ddl-log to handle errors.
sql/sql_table.cc:
  Bug#47343: InnoDB fails to clean-up after lock wait timeout on
             REORGANIZE PARTITION
  
  Fixes of the ddl-log when used as error recovery (no crash).
  When executing an entry from memory (not read from disk)
  the name_len was not set correctly.