Ceph: Fix NFS document with wrong label
Ceph: Fix NFS document with wrong label

In NFS document, the document example explain with
`-l name=nfs-busybox` label, however no corresponding label in
previous section. Fix to the label mentioned in the previous
section.

Signed-off-by: Woohyung Han <66c5f8c03226a533372a7bd43acb7801ce2bc398@gmail.com>

rook/rook,rook/rook,rook/nfs,rook/rook,rook/rook,rook/rook,rook/nfs,rook/nfs