Bug#31409 RENAME TABLE causes server crash or deadlock when used with HANDLER statements

If mysql_lock_tables fails because the lock was aborted, we need to
reset thd->some_tables_delete, otherwise we might loop indefinitely
because handler's tables are not closed in a standard way, meaning
that close_thread_tables() (which resets some_tables_deleted) is not
used.

This patch fixes sporadical failures of handler_myisam/innodb tests
which were introduced by previous fix for this bug.


sql/sql_handler.cc:
  Properly reset thd->some_tables_deleted if mysql_lock_tables
  fails for some reason.

sql/sql_handler.cc

@@ -466,6 +466,12 @@ retry:
   {
     mysql_ha_close_table(thd, tables);
     hash_tables->table= NULL;
+    /*
+      The lock might have been aborted, we need to manually reset
+      thd->some_tables_deleted because handler's tables are closed
+      in a non-standard way. Otherwise we might loop indefinitely.
+    */
+    thd->some_tables_deleted= 0;
     goto retry;
   }