[transducer] add some result of ablation (#1554)

* [transducer] add rnnt  loss  only ablation

* Update README.md

Author: Mddct

examples/aishell/rnnt/README.md

@@ -79,7 +79,7 @@ note:
 | rnnt | ctc | att | greedy | beam | rescoring | fusion |
 |------|-----|-----|--------|------|-----------|--------|
 | ✔    | ✔   | ✔   |   4.88 | 4.67 |      4.45 |   4.49 |
-| ✔    | ✔   |     |   5.56 | 5.46 |           |   5.40 |
-| ✔    |     |✔    |   5.03 |      |           |        |
-| ✔    |     |     |        |      |           |        |
-|      | ✔   | ✔   |   4.94 | 4.94 |      4.61 |        |
+| ✔    | ✔   |     |   5.56 | 5.46 |       /   |   5.40 |
+| ✔    |     | ✔   |   5.03 | 4.94 |      4.87 |    /   |
+| ✔    |     |     |   5.64 | 5.59 |       /   |    /   |
+|      | ✔   | ✔   |   4.94 | 4.94 |      4.61 |    /   |