Caused by:
5d37cac7 MDEV-33348 ALTER TABLE lock waiting stages are indistinguishable.

In that commit, progress reporting was moved to
mysql_alter_table from copy_data_between_tables.

The temporary table case wasn't taken into the consideration,
where the execution of mysql_alter_table ends earlier than usual, by the
'end_temporary' label. There, thd_progress_end has been missing.

Fix:
Add missing thd_progress_end() call in mysql_alter_table.