OPT-fix
# What does this PR do?

Quicklly fxing 3 testing issues! 

cc @patrickvonplaten @ydshieh 

Ok let's merge this one first and then I'll rebase mine here: https://github.com/huggingface/transformers/pull/17228<|||||>@younesbelkada can you also replace:

```
 tokenizer = GPT2Tokenizer.from_pretrained("patrickvonplaten/opt_gpt2_tokenizer")
```

in the embedding test with 

```
 tokenizer = GPT2Tokenizer.from_pretrained(self.path_model)
```<|||||>_The documentation is not available anymore as the PR was closed or merged._<|||||>Hi, just a nit:

This line under `OPTGenerationTest`
```
model = OPTForCausalLM.from_pretrained(self.path_model)
```
has `self.path_model` undefined.<|||||>And there are still 2 `patrickvonplaten/opt_gpt2_tokenizer` in the current version, but probably these are intended? I will leave this part for you ang Patrick.