Send zone's rootvp to untraverse()

*** 719,729 ****
  
                          /*
                           * Traverse across the mountpoint and continue the
                           * climb on the mounted-on filesystem.
                           */
!                         vp = untraverse(vp);
                          exportdir = 0;
                          continue;
                  }
  
                  /*
--- 719,729 ----
  
                          /*
                           * Traverse across the mountpoint and continue the
                           * climb on the mounted-on filesystem.
                           */
!                         vp = untraverse(vp, ne->exi_root->exi_vp);
                          exportdir = 0;
                          continue;
                  }
  
                  /*
*** 908,928 ****
  
  /*
   * Traverse backward across mountpoint from the
   * root vnode of a filesystem to its mounted-on
   * vnode.
-  *
-  * Callers to this function have confirmed the use of curzone is safe here.
   */
  vnode_t *
! untraverse(vnode_t *vp)
  {
          vnode_t *tvp, *nextvp;
  
          tvp = vp;
          for (;;) {
!                 if (!(tvp->v_flag & VROOT) && !VN_IS_CURZONEROOT(tvp))
                          break;
  
                  /* lock vfs to prevent unmount of this vfs */
                  vfs_lock_wait(tvp->v_vfsp);
  
--- 908,926 ----
  
  /*
   * Traverse backward across mountpoint from the
   * root vnode of a filesystem to its mounted-on
   * vnode.
   */
  vnode_t *
! untraverse(vnode_t *vp, vnode_t *zone_rootvp)
  {
          vnode_t *tvp, *nextvp;
  
          tvp = vp;
          for (;;) {
!                 if (!(tvp->v_flag & VROOT) && !VN_CMP(tvp, zone_rootvp))
                          break;
  
                  /* lock vfs to prevent unmount of this vfs */
                  vfs_lock_wait(tvp->v_vfsp);