fix use_amp rename after pr 17138
PR https://github.com/huggingface/transformers/pull/17138 renamed `self.use_amp` to `self.use_cuda_amp` but didn't rename it everywhere so deepspeed tests were failing. This PR fixes a few missed bits.

@sgugger 

cc: @ydshieh who reported this 
_The documentation is not available anymore as the PR was closed or merged._<|||||>Just add info: There are also 3 files in `examples/research_projects/` also use `self.amp`, but as @sgugger told me before, we should/could leave it.<|||||>I'm going to merge this before Sylvain gets a chance to look since it impacts Deepspeed's CI, which currently is failing on our tests.

Deepspeed CI is running our deepspeed tests so that they could catch any breakages caused by their changes quickly, but this requires us that we keep our deepspeed tests working.<|||||>Thanks for fixing!