[🐛BUG]: Convert tensors into the correct device

[ChenglongMa]

Convert tensors into the correct gpu/cpu device in AutoEncoderMixin

[Sherry-XLL]

Hello @ChenglongMa!

Thanks for your contributions to RecBole! We sincerely invite you to add your name and email in the header of the code in recbole/model/abstract_recommender.py as follows, in order to identify your contributions to the open-source community.

# UPDATE:
# @Time   : 2023/4/24
# @Author : ChenglongMa
# @Email  : xxx

Thank you again for your attention to our library!

[ChenglongMa]

Hello @ChenglongMa!

Thanks for your contributions to RecBole! We sincerely invite you to add your name and email in the header of the code in recbole/model/abstract_recommender.py as follows, in order to identify your contributions to the open-source community.

# UPDATE:
# @Time   : 2023/4/24
# @Author : ChenglongMa
# @Email  : xxx

Thank you again for your attention to our library!

Thanks @Sherry-XLL, I've appended my info to the author list. Very glad to be part of this community.