6659 nvlist_free(NULL) is a no-op

*** 1023,1037 ****
   * Close the handle.  Simply frees the memory associated with the handle.
   */
  void
  zpool_close(zpool_handle_t *zhp)
  {
-         if (zhp->zpool_config)
                  nvlist_free(zhp->zpool_config);
-         if (zhp->zpool_old_config)
                  nvlist_free(zhp->zpool_old_config);
-         if (zhp->zpool_props)
                  nvlist_free(zhp->zpool_props);
          free(zhp);
  }
  
  /*
--- 1023,1034 ----
*** 1546,1556 ****
                  }
          }
  
          ret = zpool_import_props(hdl, config, newname, props,
              ZFS_IMPORT_NORMAL);
-         if (props)
                  nvlist_free(props);
          return (ret);
  }
  
  static void
--- 1543,1552 ----
*** 2852,2862 ****
  
          if (nvlist_lookup_nvlist_array(tree, ZPOOL_CONFIG_CHILDREN, &child,
              &children) != 0) {
                  zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                      "Source pool is missing vdev tree"));
-                 if (zc_props)
                          nvlist_free(zc_props);
                  return (-1);
          }
  
          varray = zfs_alloc(hdl, children * sizeof (nvlist_t *));
--- 2848,2857 ----
*** 3001,3013 ****
                  for (v = 0; v < vcount; v++)
                          nvlist_free(varray[v]);
                  free(varray);
          }
          zcmd_free_nvlists(&zc);
-         if (zc_props)
                  nvlist_free(zc_props);
-         if (newconfig)
                  nvlist_free(newconfig);
          if (freelist) {
                  nvlist_free(*newroot);
                  *newroot = NULL;
          }
--- 2996,3006 ----