ceph: don't include ceph.{file,dir}.layout vxattr in listxattr()

This avoids 'cp -a' modifying layout of new files/directories.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 28549d5..c9c2b88 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -231,7 +231,7 @@
 		.name_size = sizeof("ceph.dir.layout"),
 		.getxattr_cb = ceph_vxattrcb_layout,
 		.readonly = false,
-		.hidden = false,
+		.hidden = true,
 		.exists_cb = ceph_vxattrcb_layout_exists,
 	},
 	XATTR_LAYOUT_FIELD(dir, layout, stripe_unit),
@@ -258,7 +258,7 @@
 		.name_size = sizeof("ceph.file.layout"),
 		.getxattr_cb = ceph_vxattrcb_layout,
 		.readonly = false,
-		.hidden = false,
+		.hidden = true,
 		.exists_cb = ceph_vxattrcb_layout_exists,
 	},
 	XATTR_LAYOUT_FIELD(file, layout, stripe_unit),