Try to remove assumption that zone's root vnode is marked VROOT

*** 1301,1319 ****
          vnode_t *stubvp = NULL, *vp;
  
          vp = sarg->cs->vp;
          sarg->mntdfid_set = FALSE;
  
!         /* VROOT object, must untraverse */
!         if (vp->v_flag & VROOT) {
  
                  /* extra hold for vp since untraverse might rele */
                  VN_HOLD(vp);
                  stubvp = untraverse(vp);
  
                  /*
!                  * If vp/stubvp are same, we must be at system
                   * root because untraverse returned same vp
                   * for a VROOT object.  sarg->vap was setup
                   * before we got here, so there's no need to do
                   * another getattr -- just use the one in sarg.
                   */
--- 1301,1319 ----
          vnode_t *stubvp = NULL, *vp;
  
          vp = sarg->cs->vp;
          sarg->mntdfid_set = FALSE;
  
!         /* VROOT object or zone's root, must untraverse */
!         if ((vp->v_flag & VROOT) || VN_IS_CURZONEROOT(vp)) {
  
                  /* extra hold for vp since untraverse might rele */
                  VN_HOLD(vp);
                  stubvp = untraverse(vp);
  
                  /*
!                  * If vp/stubvp are same, we must be at system-or-zone
                   * root because untraverse returned same vp
                   * for a VROOT object.  sarg->vap was setup
                   * before we got here, so there's no need to do
                   * another getattr -- just use the one in sarg.
                   */
*** 1375,1388 ****
                  if (sarg->op == NFS4ATTR_SETIT)
                          error = EINVAL;
                  break;          /* this attr is supported */
          case NFS4ATTR_GETIT:
          case NFS4ATTR_VERIT:
!                 if (! sarg->mntdfid_set)
                          error = rfs4_get_mntdfileid(cmd, sarg);
  
!                 if (! error && sarg->mntdfid_set) {
                          if (cmd == NFS4ATTR_GETIT)
                                  na->mounted_on_fileid = sarg->mounted_on_fileid;
                          else
                                  if (na->mounted_on_fileid !=
                                      sarg->mounted_on_fileid)
--- 1375,1388 ----
                  if (sarg->op == NFS4ATTR_SETIT)
                          error = EINVAL;
                  break;          /* this attr is supported */
          case NFS4ATTR_GETIT:
          case NFS4ATTR_VERIT:
!                 if (!sarg->mntdfid_set)
                          error = rfs4_get_mntdfileid(cmd, sarg);
  
!                 if (!error && sarg->mntdfid_set) {
                          if (cmd == NFS4ATTR_GETIT)
                                  na->mounted_on_fileid = sarg->mounted_on_fileid;
                          else
                                  if (na->mounted_on_fileid !=
                                      sarg->mounted_on_fileid)