Reason for the bug was an optimization for higher connect speed where we moved when global status was updated,
but forgot to update states when slave thread dies.
Fixed by adding thd->add_status_to_global() before deleting slave thread's thd.


mysys/my_delete.c:
  Added missing newline
sql/mysqld.cc:
  Use add_status_to_global()
sql/slave.cc:
  Added missing add_status_to_global()
sql/sql_class.cc:
  Use add_status_to_global()
sql/sql_class.h:
  Simplify adding local status to global by adding add_status_to_global()