MDEV-11870 Message "MariaDB Galera and flashback does not support"

Fixed the typo, updated result file and suppression in the test
file which did not work anyway

mysql-test/suite/wsrep/r/binlog_format.result

@@ -1,4 +1,4 @@
-call mtr.add_suppression("WSREP: MariaDB Galera does not support binlog format.*");
+call mtr.add_suppression("WSREP: MariaDB Galera and flashback do not support binlog format.*");
 call mtr.add_suppression("WSREP: Cannot get fake transaction ID from storage engine.");
 #
 # MDEV-4227: Galera server should stop crashing on setting binlog_format STATEMENT
@@ -8,20 +8,20 @@ Variable_name	Value
 binlog_format	ROW
 SET binlog_format=STATEMENT;
 Warnings:
-Warning	1105	MariaDB Galera and flashback does not support binlog format: STATEMENT
+Warning	1105	MariaDB Galera and flashback do not support binlog format: STATEMENT
 SHOW WARNINGS;
 Level	Code	Message
-Warning	1105	MariaDB Galera and flashback does not support binlog format: STATEMENT
+Warning	1105	MariaDB Galera and flashback do not support binlog format: STATEMENT
 SHOW VARIABLES LIKE 'binlog_format';
 Variable_name	Value
 binlog_format	STATEMENT
 CREATE TABLE IF NOT EXISTS test.t1 AS SELECT * FROM information_schema.routines WHERE 1 = 0;
 SET binlog_format=MIXED;
 Warnings:
-Warning	1105	MariaDB Galera and flashback does not support binlog format: MIXED
+Warning	1105	MariaDB Galera and flashback do not support binlog format: MIXED
 SHOW WARNINGS;
 Level	Code	Message
-Warning	1105	MariaDB Galera and flashback does not support binlog format: MIXED
+Warning	1105	MariaDB Galera and flashback do not support binlog format: MIXED
 SHOW VARIABLES LIKE 'binlog_format';
 Variable_name	Value
 binlog_format	MIXED

mysql-test/suite/wsrep/t/binlog_format.test

@@ -1,7 +1,7 @@
 --source include/have_wsrep_provider.inc
 --source include/have_binlog_format_row.inc
 
-call mtr.add_suppression("WSREP: MariaDB Galera does not support binlog format.*");
+call mtr.add_suppression("WSREP: MariaDB Galera and flashback do not support binlog format.*");
 call mtr.add_suppression("WSREP: Cannot get fake transaction ID from storage engine.");
 
 --echo #

sql/sys_vars.cc

@@ -454,12 +454,12 @@ static bool binlog_format_check(sys_var *self, THD *thd, set_var *var)
   {
     // Push a warning to the error log.
     push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN, ER_UNKNOWN_ERROR,
-                        "MariaDB Galera and flashback does not support binlog format: %s",
+                        "MariaDB Galera and flashback do not support binlog format: %s",
                         binlog_format_names[var->save_result.ulonglong_value]);
 
     if (var->type == OPT_GLOBAL)
     {
-      WSREP_ERROR("MariaDB Galera and flashback does not support binlog format: %s",
+      WSREP_ERROR("MariaDB Galera and flashback do not support binlog format: %s",
                   binlog_format_names[var->save_result.ulonglong_value]);
       return true;
     }