do sampler calculations on CPU

modules/sd_samplers_kdiffusion.py

@@ -125,7 +125,7 @@ class KDiffusionSampler(sd_samplers_common.Sampler):
         if discard_next_to_last_sigma:
             sigmas = torch.cat([sigmas[:-2], sigmas[-1:]])
 
-        return sigmas
+        return sigmas.cpu()
 
     def sample_img2img(self, p, x, noise, conditioning, unconditional_conditioning, steps=None, image_conditioning=None):
         steps, t_enc = sd_samplers_common.setup_img2img_steps(p, steps)