6940 Cannot unlink directories when over quota

@@ -2111,10 +2111,11 @@
         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);