Follow-up for a change MDEV-9040: fixed the 32-bit rdiff

mysql-test/suite/sys_vars/r/sysvars_innodb,32bit,xtradb.rdiff

@@ -592,7 +592,7 @@
 -SESSION_VALUE	NULL
 -GLOBAL_VALUE	1048576
 -GLOBAL_VALUE_ORIGIN	CONFIG
--DEFAULT_VALUE	8388608
+-DEFAULT_VALUE	16777216
 -VARIABLE_SCOPE	GLOBAL
 -VARIABLE_TYPE	BIGINT
 -VARIABLE_COMMENT	The size of the buffer which InnoDB uses to write log to the log files on disk.
@@ -666,7 +666,7 @@
 +SESSION_VALUE	NULL
 +GLOBAL_VALUE	1048576
 +GLOBAL_VALUE_ORIGIN	CONFIG
-+DEFAULT_VALUE	8388608
++DEFAULT_VALUE	16777216
 +VARIABLE_SCOPE	GLOBAL
 +VARIABLE_TYPE	INT
 +VARIABLE_COMMENT	The size of the buffer which InnoDB uses to write log to the log files on disk.