Bug#40742 MTR_VERSION=1 perl mysql-test-run.pl --start-and-exit rpl_alter does not work

mysql-test/lib/v1/mtr_cases.pl:
  The combinations file in suite uses my.cnf file syntax - thus the options in the
  combinations file should not have -- prefixed.
  Add -- to the option while reading it from file.

mysql-test/lib/v1/mtr_cases.pl

@@ -369,7 +369,7 @@ sub collect_one_suite($)
 	my $comb= {};
 	$comb->{name}= $group->name();
         foreach my $option ( $group->options() ) {
-	  push(@{$comb->{comb_opt}}, $option->name()."=".$option->value());
+	  push(@{$comb->{comb_opt}}, "--".$option->name()."=".$option->value());
 	}
 	push(@combinations, $comb);
       }