server: xtfs_scrub: Fixed problem that the wrong variable was used to...

server: xtfs_scrub: Fixed problem that the wrong variable was used to determine if the file size has to be corrected on the MRC.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@3607 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534