Move the assignment of testfile after the sourcing of the common.* files to
make sure TEST_DIR is already defined - without this we end up creating
the file on the root filesystem, which may not support large enough files.
Also add a sync after the mkfs.xfs invocation, as losetup -d might fail
the loop device deletion with -EBUSY otherwise.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>