HadoopClient: fixed a bug leading to failures while create-on-opening a file...

HadoopClient: fixed a bug leading to failures while create-on-opening a file through the client-file abstraction

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@1604 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534