qa: use new hex rep of inode

qa: use new hex rep of inode

Resolves a failure from QA:

    2017-08-02T19:23:27.489 INFO:tasks.cephfs_test_runner:======================================================================
    2017-08-02T19:23:27.489 INFO:tasks.cephfs_test_runner:FAIL: test_oversize (tasks.cephfs.test_fragment.TestFragmentation)
    2017-08-02T19:23:27.489 INFO:tasks.cephfs_test_runner:----------------------------------------------------------------------
    2017-08-02T19:23:27.490 INFO:tasks.cephfs_test_runner:Traceback (most recent call last):
    2017-08-02T19:23:27.490 INFO:tasks.cephfs_test_runner:  File "/home/teuthworker/src/git.ceph.com_ceph-c_wip-pdonnell-testing-20170802/qa/tasks/cephfs/test_fragment.py", line 71, in test_oversize
    2017-08-02T19:23:27.490 INFO:tasks.cephfs_test_runner:    self.assertEqual(frags[0]['dirfrag'], "10000000000.0*")
    2017-08-02T19:23:27.490 INFO:tasks.cephfs_test_runner:AssertionError: u'0x10000000000.0*' != '10000000000.0*'
    2017-08-02T19:23:27.490 INFO:tasks.cephfs_test_runner:

Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>