MDEV-21452 fixup: Remove an unused variable

storage/innobase/btr/btr0btr.cc

@@ -44,8 +44,6 @@ Created 6/2/1994 Heikki Tuuri
 #include "dict0boot.h"
 #include "row0sel.h" /* row_search_max_autoinc() */
 
-Atomic_counter<uint32_t> btr_validate_index_running;
-
 /**************************************************************//**
 Checks if the page in the cursor can be merged with given page.
 If necessary, re-organize the merge_page.
@@ -5035,7 +5033,6 @@ btr_validate_index(
 
 	ulint	n = btr_page_get_level(root);
 
-	btr_validate_index_running++;
 	for (ulint i = 0; i <= n; ++i) {
 
 		if (!btr_validate_level(index, trx, n - i, lockout)) {
@@ -5044,15 +5041,6 @@ btr_validate_index(
 	}
 
 	mtr_commit(&mtr);
-	/* In theory we need release barrier here, so that
-	btr_validate_index_running decrement is guaranteed to
-	happen after latches are released.
-
-	Original code issued SEQ_CST on update and non-atomic
-	access on load. Which means it had broken synchronisation
-	as well. */
-	btr_validate_index_running--;
-
 	return(err);
 }
 

storage/innobase/include/btr0btr.h

@@ -2,7 +2,7 @@
 
 Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2014, 2021, MariaDB Corporation.
+Copyright (c) 2014, 2022, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -25,8 +25,7 @@ The B-tree
 Created 6/2/1994 Heikki Tuuri
 *******************************************************/
 
-#ifndef btr0btr_h
-#define btr0btr_h
+#pragma once
 
 #include "dict0dict.h"
 #include "data0data.h"
@@ -681,6 +680,3 @@ btr_lift_page_up(
 /****************************************************************
 Global variable controlling if scrubbing should be performed */
 extern my_bool srv_immediate_scrub_data_uncompressed;
-extern Atomic_counter<uint32_t> btr_validate_index_running;
-
-#endif