MDEV-14193 innodb.log_file_name failed in buildbot with exception

Problem:
=======
- innodb.log_file_name fails if it executes after
innodb.lock_insert_into_empty in few cases.
innodb.lock_insert_into_empty test case failed to
cleanup the table t2. Rollback of create..select fails
to remove the table when it fails to acquire the
innodb statistics table. This leads to rename table
in log_file_name test case fails.

Solution:
========
- Cleanup the table t2 explictly after resetting
innodb_lock_wait_timeout variable in
innodb.lock_insert_into_empty test case.

mysql-test/suite/innodb/r/lock_insert_into_empty.result

@@ -47,6 +47,9 @@ CREATE TABLE t1 (k INT PRIMARY KEY) ENGINE=InnoDB;
 INSERT INTO t1 SET k=1;
 START TRANSACTION;
 INSERT INTO t1 SET k=2;
+SELECT count(*) > 0 FROM mysql.innodb_index_stats lock in share mode;
+count(*) > 0
+1
 connect  con1,localhost,root,,test;
 SET innodb_lock_wait_timeout=0;
 CREATE TABLE t2 (pk INT AUTO_INCREMENT PRIMARY KEY) ENGINE=InnoDB
@@ -54,4 +57,6 @@ AS SELECT k FROM t1;
 ERROR HY000: Lock wait timeout exceeded; try restarting transaction
 disconnect con1;
 connection default;
+SET innodb_lock_wait_timeout=default;
 DROP TABLE t1;
+DROP TABLE IF EXISTS t2;

mysql-test/suite/innodb/t/lock_insert_into_empty.test

@@ -51,6 +51,7 @@ CREATE TABLE t1 (k INT PRIMARY KEY) ENGINE=InnoDB;
 INSERT INTO t1 SET k=1;
 START TRANSACTION;
 INSERT INTO t1 SET k=2;
+SELECT count(*) > 0 FROM mysql.innodb_index_stats lock in share mode;
 
 --connect (con1,localhost,root,,test)
 SET innodb_lock_wait_timeout=0;
@@ -59,5 +60,6 @@ CREATE TABLE t2 (pk INT AUTO_INCREMENT PRIMARY KEY) ENGINE=InnoDB
 AS SELECT k FROM t1;
 --disconnect con1
 --connection default
-
+SET innodb_lock_wait_timeout=default;
 DROP TABLE t1;
+DROP TABLE IF EXISTS t2;