Fix example int8_inference_huggingface.py

[alexrs]

What

When running the example int8_inference_huggingface.py I was getting the error:

ValueError: Tokenizer class LLaMATokenizer does not exist or is not currently imported

when using the latest transformers=4.29.2. According to this issue:

the tokenizer in the config on the hub points to LLaMATokenizer. However, the tokenizer in the library is LlamaTokenizer.
This is likely due to the configuration files being created before the final PR was merged in.

(See comment)

Fix

Use LlamaForCausalLM and LlamaTokenizer instead of Auto... classes works as expected.

Test plan

• Run python examples/int8_inference_huggingface.py
• Obtained the following output:

Hamburg is in which country?
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.
The capital of Germany is Berlin.