Fix the order of casts for onnx inpainting (#1338)

Author: anton-l

src/diffusers/pipelines/stable_diffusion/pipeline_onnx_stable_diffusion_inpaint.py

@@ -409,8 +409,8 @@ def __call__(
             latent_model_input = np.concatenate([latents] * 2) if do_classifier_free_guidance else latents
             # concat latents, mask, masked_image_latnets in the channel dimension
             latent_model_input = self.scheduler.scale_model_input(torch.from_numpy(latent_model_input), t)
-            latent_model_input = np.concatenate([latent_model_input, mask, masked_image_latents], axis=1)
             latent_model_input = latent_model_input.cpu().numpy()
+            latent_model_input = np.concatenate([latent_model_input, mask, masked_image_latents], axis=1)
 
             # predict the noise residual
             timestep = np.array([t], dtype=timestep_dtype)