6940 Cannot unlink directories when over quota

*** 2111,2120 ****
--- 2111,2121 ----
          dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
          dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
          dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
          zfs_sa_upgrade_txholds(tx, zp);
          zfs_sa_upgrade_txholds(tx, dzp);
+         dmu_tx_mark_netfree(tx);
          error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
          if (error) {
                  rw_exit(&zp->z_parent_lock);
                  rw_exit(&zp->z_name_lock);
                  zfs_dirent_unlock(dl);