[pl] restore lr logging behavior for glue, ner examples
Author: stas00
Pull request: yes

2 more fixes for https://github.com/huggingface/transformers/pull/6027

1. restore the original code and add what was there already, instead of a complex line of code.

2. restore removed `rate` field - solve the missing bit



Comments:
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/6314?src=pr&el=h1) Report
> Merging [#6314](https://codecov.io/gh/huggingface/transformers/pull/6314?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/be1520d3a3c09d729649c49fa3163bd938b6a238&el=desc) will **decrease** coverage by `0.85%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/6314/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/6314?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #6314      +/-   ##
==========================================
- Coverage   79.93%   79.08%   -0.86%     
==========================================
  Files         153      153              
  Lines       27888    27888              
==========================================
- Hits        22293    22054     -239     
- Misses       5595     5834     +239     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/6314?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/tokenization\_xlm.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90b2tlbml6YXRpb25feGxtLnB5) | `16.26% <0.00%> (-66.67%)` | :arrow_down: |
| [src/transformers/tokenization\_marian.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90b2tlbml6YXRpb25fbWFyaWFuLnB5) | `66.66% <0.00%> (-32.50%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_bert.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9iZXJ0LnB5) | `69.06% <0.00%> (-27.52%)` | :arrow_down: |
| [src/transformers/tokenization\_openai.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90b2tlbml6YXRpb25fb3BlbmFpLnB5) | `71.21% <0.00%> (-12.88%)` | :arrow_down: |
| [src/transformers/tokenization\_gpt2.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90b2tlbml6YXRpb25fZ3B0Mi5weQ==) | `87.50% <0.00%> (-9.73%)` | :arrow_down: |
| [src/transformers/tokenization\_transfo\_xl.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90b2tlbml6YXRpb25fdHJhbnNmb194bC5weQ==) | `33.56% <0.00%> (-8.93%)` | :arrow_down: |
| [src/transformers/tokenization\_utils\_base.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90b2tlbml6YXRpb25fdXRpbHNfYmFzZS5weQ==) | `92.08% <0.00%> (-1.39%)` | :arrow_down: |
| [src/transformers/modeling\_bert.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ19iZXJ0LnB5) | `88.26% <0.00%> (-0.17%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_distilbert.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9kaXN0aWxiZXJ0LnB5) | `97.41% <0.00%> (+32.94%)` | :arrow_up: |
| [src/transformers/tokenization\_albert.py](https://codecov.io/gh/huggingface/transformers/pull/6314/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90b2tlbml6YXRpb25fYWxiZXJ0LnB5) | `87.50% <0.00%> (+58.65%)` | :arrow_up: |

------

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> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/6314?src=pr&el=footer). Last update [be1520d...6321287](https://codecov.io/gh/huggingface/transformers/pull/6314?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).


How do we know this works?

> How do we know this works?

I described what it did in the first comment:
1. use public API instead of digging into PL internals
2.  restoring bits removed by https://github.com/huggingface/transformers/pull/6027 you have to compare against the original (pre-6027) see the second to last part of the diff: https://github.com/huggingface/transformers/pull/6027/files#diff-6cf9887b73b621b2d881039a61ccfa5fR47
```
        # tensorboard_logs = {"loss": loss, "rate": self.lr_scheduler.get_last_lr()[-1]}
        tensorboard_logs = {"loss": loss}
```
why `rate` was removed?

i.e. this PR is restoring, not changing anything. PR6027 did change behavior w/o testing the change.

note: This does not effect seq2seq/ because of `Seq2SeqLoggingCallback`

Thanks @stas00 !