Revert "MDEV-29091: Correct event_name in PFS for wait caused by FOR UPDATE"

This reverts commit 03c9a4ef.

The fix is wrong. It was doing this: if the uninitialized
wait->m_class has some specific value, then don't initialize it.

mysql-test/suite/perfschema/r/events_waits_current_MDEV-29091.result

-SET default_storage_engine=InnoDB;
-SELECT @save_instrument_enabled := ENABLED
-, @save_instrument_timed := TIMED
-FROM performance_schema.setup_instruments
-WHERE NAME = 'wait/lock/table/sql/handler';
-@save_instrument_enabled := ENABLED	@save_instrument_timed := TIMED
-YES	YES
-SELECT @save_consumer_enabled := ENABLED
-FROM performance_schema.setup_consumers
-WHERE NAME = 'events_waits_current';
-@save_consumer_enabled := ENABLED
-YES
-UPDATE performance_schema.setup_instruments 
-SET ENABLED = 'YES', TIMED = 'YES'
-WHERE NAME = 'wait/lock/table/sql/handler';
-UPDATE performance_schema.setup_consumers 
-SET ENABLED = 'YES' 
-WHERE NAME = 'events_waits_current';
-CREATE TABLE t1 (id1 INT(11), col1 VARCHAR (200));
-INSERT INTO t1 VALUES (1, 'aa');
-INSERT INTO t1 VALUES (2, 'bb');
-connect  con1,localhost,root,,test;
-connect  con2,localhost,root,,test;
-connection con1;
-START TRANSACTION;
-connection con2;
-START TRANSACTION;
-SELECT id1 FROM t1 WHERE id1=1 FOR UPDATE;
-connection default;
-SELECT event_name FROM performance_schema.events_waits_current
-WHERE event_name LIKE '%wait/lock/table/sql/handler%';
-event_name
-UPDATE performance_schema.setup_instruments 
-SET ENABLED = @save_instrument_enabled, TIMED = @save_instrument_timed
-WHERE NAME = 'wait/lock/table/sql/handler';
-UPDATE performance_schema.setup_consumers 
-SET ENABLED = @save_consumer_enabled
-WHERE NAME = 'events_waits_current';
-disconnect con1;
-disconnect con2;
-DROP TABLE t1;

mysql-test/suite/perfschema/t/events_waits_current_MDEV-29091.test

-#
-# proper event name wait/lock/table/sql/handler recorded in
-# PERFORMANCE_SCHEMA.EVENTS_WAITS_CURRENT. Before this fix, it was
-# labeled as wait/io/table/sql/handler.
-# 
-
---source include/have_innodb.inc
---source include/have_perfschema.inc
---source include/not_embedded.inc
-
-SET default_storage_engine=InnoDB;
-
-SELECT @save_instrument_enabled := ENABLED
-, @save_instrument_timed := TIMED
-FROM performance_schema.setup_instruments
-WHERE NAME = 'wait/lock/table/sql/handler';
-
-SELECT @save_consumer_enabled := ENABLED
-FROM performance_schema.setup_consumers
-WHERE NAME = 'events_waits_current';
-
-UPDATE performance_schema.setup_instruments 
-SET ENABLED = 'YES', TIMED = 'YES'
-WHERE NAME = 'wait/lock/table/sql/handler';
-
-UPDATE performance_schema.setup_consumers 
-SET ENABLED = 'YES' 
-WHERE NAME = 'events_waits_current';
-
-CREATE TABLE t1 (id1 INT(11), col1 VARCHAR (200));
-INSERT INTO t1 VALUES (1, 'aa');
-INSERT INTO t1 VALUES (2, 'bb');
- 
-connect (con1,localhost,root,,test);
-connect (con2,localhost,root,,test);
- 
-connection con1;
-START TRANSACTION;
-let $wait_condition=
-  SELECT id1 FROM t1 WHERE id1=1 FOR UPDATE;
---source include/wait_condition.inc
- 
-connection con2;
-START TRANSACTION;
-send SELECT id1 FROM t1 WHERE id1=1 FOR UPDATE;
- 
-connection default;
-SELECT event_name FROM performance_schema.events_waits_current
-WHERE event_name LIKE '%wait/lock/table/sql/handler%';
- 
-# clean up
-UPDATE performance_schema.setup_instruments 
-SET ENABLED = @save_instrument_enabled, TIMED = @save_instrument_timed
-WHERE NAME = 'wait/lock/table/sql/handler';
-
-UPDATE performance_schema.setup_consumers 
-SET ENABLED = @save_consumer_enabled
-WHERE NAME = 'events_waits_current';
-
-disconnect con1;
-disconnect con2;
-DROP TABLE t1;

storage/perfschema/pfs.cc

@@ -3068,8 +3068,7 @@ pfs_start_table_io_wait_v1(PSI_table_locker_state *state,
 
       PFS_table_share *share= pfs_table->m_share;
       wait->m_thread_internal_id= pfs_thread->m_thread_internal_id;
-      if (wait->m_class == NULL || wait->m_class->m_type != PFS_CLASS_TABLE_LOCK)
-        wait->m_class= &global_table_io_class;
+      wait->m_class= &global_table_io_class;
       wait->m_timer_start= timer_start;
       wait->m_timer_end= 0;
       wait->m_object_instance_addr= pfs_table->m_identity;