MDEV-32933: Skip statement and mix mode for binlog.flashback

The binlog.flashback test tries to run using the stmt and mix
binlog_format combinations (because it includes have_log_bin.inc),
yet are meaningless tests because the server starts with the
--flashback option, forcing binlog_format=row.

This patch optimizes test time by removing the stmt and mix format
combinations from running.

Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>

mysql-test/suite/binlog/t/flashback.test

---source include/have_log_bin.inc
+--source include/have_binlog_format_row.inc
 --source include/have_innodb.inc
 
 --echo #
@@ -101,7 +101,7 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 --replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
 --exec $MYSQL_BINLOG -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_original_1.sql
 --exec $MYSQL_BINLOG -B -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_1.sql
---exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_1.sql;"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_1.sql;"
 
 SELECT * FROM t1;
 
@@ -126,7 +126,7 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 --replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
 --exec $MYSQL_BINLOG -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_original_2.sql
 --exec $MYSQL_BINLOG -B -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_2.sql
---exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_2.sql;"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_2.sql;"
 
 SELECT * FROM t1;
 
@@ -160,7 +160,7 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 --replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
 --exec $MYSQL_BINLOG -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_original_3.sql
 --exec $MYSQL_BINLOG -B -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_3.sql
---exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_3.sql;"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_3.sql;"
 
 SELECT * FROM t1;
 
@@ -202,7 +202,7 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 --replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
 --exec $MYSQL_BINLOG -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_original_4.sql
 --exec $MYSQL_BINLOG -B $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_4.sql
---exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_4.sql;"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_4.sql;"
 
 SELECT * FROM t1;
 SELECT * FROM t2;
@@ -247,7 +247,7 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 --replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
 --exec $MYSQL_BINLOG -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_original_5.sql
 --exec $MYSQL_BINLOG -B $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_5.sql
---exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_5.sql;"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_5.sql;"
 
 SELECT * FROM t1;
 
@@ -323,7 +323,7 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 --replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
 --exec $MYSQL_BINLOG --database=world --table=city -vv $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_original_6.sql
 --exec $MYSQL_BINLOG --database=world --table=city -B $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_6.sql
---exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_6.sql;"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_6.sql;"
 
 SELECT * FROM world.city;
 
@@ -355,7 +355,7 @@ FLUSH LOGS;
 --source include/assert.inc
 
 --exec $MYSQL_BINLOG -vv -B --read-from-remote-server --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000002> $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_7.sql
---exec $MYSQL -e "SET binlog_format= ROW; source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_7.sql;"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/mysqlbinlog_row_flashback_7.sql;"
 
 --echo # 6- Rows must be present upon restoring from flashback
 --let $assert_cond= COUNT(*) = 6 FROM t1