Fix bug in determining if subfolder is parent.

Author: Jmcfar

src/main/java/com/amazonaws/codedeploy/AWSCodeDeployPublisher.java

@@ -250,7 +250,7 @@ private boolean isSubDirectory(FilePath parent, FilePath child) {
             if (parent.equals(parentFolder)) {
                 return true;
             }
-            parentFolder = child.getParent();
+            parentFolder = parentFolder.getParent();
         }
         return false;
     }