build: Add missing dep from vfs_nfs4acl_xattr to NDR_NFS4ACL

Reviewed-by: Andreas Schneider <asn@samba.org>

Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Tue May 14 01:23:17 CEST 2013 on sn-devel-104