Exit transfer loop when output fd is closed

If input fd is closed due to EOF, we need to continue transferring IO to handle the
case:

   echo -e "print('hello world')\n" | ssh recuser@localhost "python3"

Otherwise, exit when EOF is received from source.

lib/tlog/rec.c

@@ -967,6 +967,10 @@ tlog_rec_transfer(struct tlog_errs    **perrs,
             }
         } else if (tlog_pkt_is_eof(&pkt)) {
             tlog_sink_io_close(tty_sink, pkt.data.io.output);
+            /* Continue if only input was closed */
+            if (pkt.data.io.output) {
+                break;
+            }
         }
     }