fix a bug in StableDiffusionUpscalePipeline.run_safety_checker (#4886)

fix
Co-authored-by: yiyixuxu <yixu310@gmail,com>

src/diffusers/pipelines/stable_diffusion/pipeline_stable_diffusion_upscale.py

@@ -165,10 +165,10 @@ class StableDiffusionUpscalePipeline(DiffusionPipeline, TextualInversionLoaderMi
         # We'll offload the last model manually.
         self.final_offload_hook = hook
 
-    # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline.run_safety_checker
     def run_safety_checker(self, image, device, dtype):
         if self.safety_checker is not None:
-            safety_checker_input = self.feature_extractor(self.numpy_to_pil(image), return_tensors="pt").to(device)
+            feature_extractor_input = self.image_processor.postprocess(image, output_type="pil")
+            safety_checker_input = self.feature_extractor(feature_extractor_input, return_tensors="pt").to(device)
             image, nsfw_detected, watermark_detected = self.safety_checker(
                 images=image,
                 clip_input=safety_checker_input.pixel_values.to(dtype=dtype),