Bug #58482 mtr doesn't use suite names from individually specified test cases

It does work in general, the problem here was that the test name
'alter_table' matches 'main.alter_table-big' which has already been found.
Fixed by matching more explicitly (with/without suite name)

mysql-test/lib/mtr_cases.pm

@@ -143,7 +143,7 @@ sub collect_test_cases ($$$) {
       {
 	last unless $opt_reorder;
 	# test->{name} is always in suite.name format
-	if ( $test->{name} =~ /.*\.$tname/ )
+	if ( $test->{name} =~ /^$sname.*\.$tname$/ )
 	{
 	  $found= 1;
 	  last;