Reuse IOExceptionList.

Author: Gary Gregory

src/test/java/org/apache/commons/io/FileUtilsCleanDirectoryTestCase.java

@@ -111,7 +111,8 @@ public void testThrowsOnCannotDeleteFile() throws Exception {
             FileUtils.cleanDirectory(top);
             fail("expected IOException");
         } catch (final IOException e) {
-            assertEquals("Unable to delete file: " + file.getAbsolutePath(), e.getMessage());
+            final IOExceptionList list = (IOExceptionList) e;  
+            assertEquals("Unable to delete file: " + file.getAbsolutePath(), list.getCause(0).getMessage());
         } finally {
             chmod(top, 755, false);
         }