use selected device instead of always cuda for UniPC sampler

modules/models/diffusion/uni_pc/sampler.py

@@ -3,7 +3,8 @@
 import torch
 
 from .uni_pc import NoiseScheduleVP, model_wrapper, UniPC
-from modules import shared
+from modules import shared, devices
+
 
 class UniPCSampler(object):
     def __init__(self, model, **kwargs):
@@ -16,8 +17,8 @@ class UniPCSampler(object):
 
     def register_buffer(self, name, attr):
         if type(attr) == torch.Tensor:
-            if attr.device != torch.device("cuda"):
-                attr = attr.to(torch.device("cuda"))
+            if attr.device != devices.device:
+                attr = attr.to(devices.device)
         setattr(self, name, attr)
 
     def set_hooks(self, before_sample, after_sample, after_update):