fix Swin Transformer inplace mutation (#6266)
fix Swin Transformer inplace mutation (#6266)

* fix inplace mutation

* Different attn shouldn't share the same attribute

* a simpler solution

Co-authored-by: YosuaMichael <5423970700750714849a25ac15d35a882e5ae483@gmail.com>
pytorch/vision,pytorch/vision,pytorch/vision,pytorch/vision,pytorch/vision,pytorch/vision