Update example usage to avoid undefined `pipe`

Update example usage to avoid undefined `pipe`
```
vae = ConsistencyDecoderVAE.from_pretrained("openai/consistency-decoder", torch_dtype=pipe.torch_dtype)
^^^^
NameError: name 'pipe' is not defined
```

README.md

@@ -17,9 +17,9 @@ To original code repository can be found [here](https://github.com/openai/consis
 import torch
 from diffusers import DiffusionPipeline, ConsistencyDecoderVAE
 
-vae = ConsistencyDecoderVAE.from_pretrained("openai/consistency-decoder", torch_dtype=pipe.torch_dtype)
+vae = ConsistencyDecoderVAE.from_pretrained("openai/consistency-decoder", torch_dtype=torch.float16)
 pipe = StableDiffusionPipeline.from_pretrained(
-    "runwayml/stable-diffusion-v1-5", vae=vae, torch_dtype=torch.float16
+    "runwayml/stable-diffusion-v1-5", vae=vae, torch_dtype=vae.dtype
 ).to("cuda")
 
 pipe("horse", generator=torch.manual_seed(0)).images