fix have_debug_sync.inc

remove unused require files

mysql-test/include/have_debug_sync.inc

---require r/have_debug_sync.require
-disable_query_log;
-let $value= query_get_value(SHOW VARIABLES LIKE 'debug_sync', Value, 1);
-eval SELECT ('$value' LIKE 'ON %') AS debug_sync;
-enable_query_log;
+if (`select @@debug_sync not like 'ON %'`) {
+  --skip Needs a debug_sync enabled
+}

mysql-test/r/have_debug_sync.require

-debug_sync
-1

mysql-test/r/is_debug_build.require

-instr(version(), "debug") > 0
-1

mysql-test/r/server_id.require

-Variable_name	Value
-server_id	1

mysql-test/r/server_id1.require

-Variable_name	Value
-server_id	102

mysql-test/r/testdb_only.require

-Variable_name    	Value
-use extern server	NO

mysql-test/r/windows.require

-TRUE
-1