Fix potential test conflict

Cf. <https://ci.appveyor.com/project/php/php-src/builds/31564684/job/k9u3xv860fao3n2e#L5578>

Author: cmb69

ext/standard/tests/file/windows_mb_path/bug54028_2.phpt

@@ -16,7 +16,7 @@ skip_if_no_required_exts();
 
 include __DIR__ . DIRECTORY_SEPARATOR . "util.inc";
 
-$prefix = __DIR__ . DIRECTORY_SEPARATOR . "testBug54028" . DIRECTORY_SEPARATOR;
+$prefix = __DIR__ . DIRECTORY_SEPARATOR . "testBug54028_2" . DIRECTORY_SEPARATOR;
 
 $dirs = array("a", "ソ", "ゾ", "şŞıİğĞ", "多国語", "王", "汚れて掘る");