NFS Auth per-zone needs better cleanup

*** 278,287 ****
--- 278,290 ----
  
          list_destroy(&nag->refreshq_queue);
          cv_destroy(&nag->refreshq_cv);
          mutex_destroy(&nag->refreshq_lock);
          mutex_destroy(&nag->mountd_lock);
+         /* Extra cleanup. */
+         if (nag->mountd_dh != NULL)
+                 door_ki_rele(nag->mountd_dh);
          kmem_free(nag, sizeof (*nag));
  }
  
  /*
   * Convert the address in a netbuf to