remove pointless test

mysql-test/suite/sys_vars/r/innodb_purge_threads_basic.result

-SELECT COUNT(@@GLOBAL.innodb_purge_threads);
-COUNT(@@GLOBAL.innodb_purge_threads)
-1
-1 Expected
-SELECT COUNT(@@innodb_purge_threads);
-COUNT(@@innodb_purge_threads)
-1
-1 Expected
-SET @@GLOBAL.innodb_purge_threads=1;
-ERROR HY000: Variable 'innodb_purge_threads' is a read only variable
-Expected error 'Read-only variable'
-SELECT innodb_purge_threads = @@SESSION.innodb_purge_threads;
-ERROR 42S22: Unknown column 'innodb_purge_threads' in 'field list'
-Expected error 'Read-only variable'
-SELECT @@GLOBAL.innodb_purge_threads = VARIABLE_VALUE
-FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES
-WHERE VARIABLE_NAME='innodb_purge_threads';
-@@GLOBAL.innodb_purge_threads = VARIABLE_VALUE
-1
-1 Expected
-SELECT COUNT(VARIABLE_VALUE)
-FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 
-WHERE VARIABLE_NAME='innodb_purge_threads';
-COUNT(VARIABLE_VALUE)
-1
-1 Expected
-SELECT @@innodb_purge_threads = @@GLOBAL.innodb_purge_threads;
-@@innodb_purge_threads = @@GLOBAL.innodb_purge_threads
-1
-1 Expected
-SELECT COUNT(@@local.innodb_purge_threads);
-ERROR HY000: Variable 'innodb_purge_threads' is a GLOBAL variable
-Expected error 'Variable is a GLOBAL variable'
-SELECT COUNT(@@SESSION.innodb_purge_threads);
-ERROR HY000: Variable 'innodb_purge_threads' is a GLOBAL variable
-Expected error 'Variable is a GLOBAL variable'
-SELECT VARIABLE_NAME, VARIABLE_VALUE
-FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES
-WHERE VARIABLE_NAME = 'innodb_purge_threads';
-VARIABLE_NAME	VARIABLE_VALUE
-INNODB_PURGE_THREADS	4

mysql-test/suite/sys_vars/t/innodb_purge_threads_basic.test

-# Variable name: innodb_purge_threads
-# Scope: Global
-# Access type: Static
-# Data type: numeric
-
---source include/have_innodb.inc
-
-SELECT COUNT(@@GLOBAL.innodb_purge_threads);
---echo 1 Expected
-
-SELECT COUNT(@@innodb_purge_threads);
---echo 1 Expected
-
---error ER_INCORRECT_GLOBAL_LOCAL_VAR
-SET @@GLOBAL.innodb_purge_threads=1;
---echo Expected error 'Read-only variable'
-
---Error ER_BAD_FIELD_ERROR
-SELECT innodb_purge_threads = @@SESSION.innodb_purge_threads;
---echo Expected error 'Read-only variable'
-
---disable_warnings
-SELECT @@GLOBAL.innodb_purge_threads = VARIABLE_VALUE
-FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES
-WHERE VARIABLE_NAME='innodb_purge_threads';
---enable_warnings
---echo 1 Expected
-
---disable_warnings
-SELECT COUNT(VARIABLE_VALUE)
-FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 
-WHERE VARIABLE_NAME='innodb_purge_threads';
---enable_warnings
---echo 1 Expected
-
-SELECT @@innodb_purge_threads = @@GLOBAL.innodb_purge_threads;
---echo 1 Expected
-
---Error ER_INCORRECT_GLOBAL_LOCAL_VAR
-SELECT COUNT(@@local.innodb_purge_threads);
---echo Expected error 'Variable is a GLOBAL variable'
-
---Error ER_INCORRECT_GLOBAL_LOCAL_VAR
-SELECT COUNT(@@SESSION.innodb_purge_threads);
---echo Expected error 'Variable is a GLOBAL variable'
-
-# Check the default value
---disable_warnings
-SELECT VARIABLE_NAME, VARIABLE_VALUE
-FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES
-WHERE VARIABLE_NAME = 'innodb_purge_threads';
---enable_warnings
-