MDEV-7318: Fix a test case

Author: dr-m

mysql-test/suite/innodb/r/innodb-alter-debug.result

@@ -105,5 +105,5 @@ CREATE TABLE t (c1 INT, c2 INT, KEY i2 (c2)) ENGINE=INNODB;
 SET DEBUG_DBUG= '+d,ib_rename_index_fail1';
 ALTER TABLE t RENAME INDEX i2 to x, ALGORITHM=INPLACE;
 ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
-SET DEBUG_DBUG= '-d,ib_rename_index_fail1';
+SET DEBUG_DBUG = @saved_debug_dbug;
 DROP TABLE t;

mysql-test/suite/innodb/t/innodb-alter-debug.test

@@ -130,9 +130,6 @@ reap;
 UNLOCK TABLES;
 DROP TABLE t1;
 
-# Wait till all disconnects are completed
---source include/wait_until_count_sessions.inc
-
 --echo #
 --echo # MDEV-7318 RENAME INDEX
 --echo #
@@ -141,6 +138,9 @@ CREATE TABLE t (c1 INT, c2 INT, KEY i2 (c2)) ENGINE=INNODB;
 SET DEBUG_DBUG= '+d,ib_rename_index_fail1';
 -- error ER_LOCK_DEADLOCK
 ALTER TABLE t RENAME INDEX i2 to x, ALGORITHM=INPLACE;
-SET DEBUG_DBUG= '-d,ib_rename_index_fail1';
+SET DEBUG_DBUG = @saved_debug_dbug;
 
 DROP TABLE t;
+
+# Wait till all disconnects are completed
+--source include/wait_until_count_sessions.inc