qa/workunits/fs/misc/layout_vxattrs: ceph.file.layout is not listed

As of 08a3d6bd428c5e78dd4a10e6ee97540f66f9729c.  A similar change was made
in the kernel.

Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 4f9f7f878953b29cd5f56a8e0834832d6e3a9cec)