Fix docs for torch.real (#78644)
Non-complex types are supported
```python
>>> import torch
>>> z = torch.zeros(5)
>>> torch.real(z.float())
tensor([0., 0., 0., 0., 0.])
>>> torch.real(z.int())
tensor([0, 0, 0, 0, 0], dtype=torch.int32)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78644
Approved by: https://github.com/mruberry, https://github.com/anjali411
