Cleanup: Remove unused OS_DATA_TEMP_FILE

This had been originally added in
mysql/mysql-server@192bb15
with the motivation to disable O_DIRECT for the dedicated tablespace
for temporary tables. In MariaDB Server,
commit 5eb5395 (MDEV-12227)
should be a better solution.

The code became orphaned later in
mysql/mysql-server@c61244c
and it had been applied to MariaDB Server 10.2.2 in
commit 2e814d4 and
commit fec844a.

Thanks to Vladislav Vaintroub for spotting this.

storage/innobase/include/os0file.h

@@ -2,7 +2,7 @@
 
 Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2009, Percona Inc.
-Copyright (c) 2013, 2020, MariaDB Corporation.
+Copyright (c) 2013, 2021, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted
 by Percona Inc.. Those modifications are
@@ -160,7 +160,6 @@ static const ulint OS_FILE_NORMAL = 62;
 /** Types for file create @{ */
 static const ulint OS_DATA_FILE = 100;
 static const ulint OS_LOG_FILE = 101;
-static const ulint OS_DATA_TEMP_FILE = 102;
 static const ulint OS_DATA_FILE_NO_O_DIRECT = 103;
 /* @} */
 

storage/innobase/os/os0file.cc

@@ -2,7 +2,7 @@
 
 Copyright (c) 1995, 2019, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2009, Percona Inc.
-Copyright (c) 2013, 2020, MariaDB Corporation.
+Copyright (c) 2013, 2021, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted
 by Percona Inc.. Those modifications are
@@ -3007,7 +3007,6 @@ os_file_create_func(
 
 	ut_a(type == OS_LOG_FILE
 	     || type == OS_DATA_FILE
-	     || type == OS_DATA_TEMP_FILE
 	     || type == OS_DATA_FILE_NO_O_DIRECT);
 
 	ut_a(purpose == OS_FILE_AIO || purpose == OS_FILE_NORMAL);
@@ -3055,7 +3054,7 @@ os_file_create_func(
 	/* We disable OS caching (O_DIRECT) only on data files */
 	if (!read_only
 	    && *success
-	    && (type != OS_LOG_FILE && type != OS_DATA_TEMP_FILE
+	    && (type != OS_LOG_FILE
 		&& type != OS_DATA_FILE_NO_O_DIRECT)
 	    && (srv_file_flush_method == SRV_O_DIRECT
 		|| srv_file_flush_method == SRV_O_DIRECT_NO_FSYNC)) {