Apply suggestions from code review

Author: yiyixuxu

src/diffusers/pipelines/pipeline_utils.py

@@ -466,7 +466,7 @@ def module_is_offloaded(module):
             module_is_sequentially_offloaded(module) for _, module in self.components.items()
         )
 
-        is_pipeline_device_mapped = hasattr(self, "hf_device_map") and self.hf_device_map is not None and len(self.hf_device_map) > 1
+        is_pipeline_device_mapped = self.hf_device_map is not None and len(self.hf_device_map) > 1
         if is_pipeline_device_mapped:
             raise ValueError(
                 "It seems like you have activated a device mapping strategy on the pipeline which doesn't allow explicit device placement using `to()`. You can call `reset_device_map()` to remove the existing device map from the pipeline."
@@ -483,7 +483,6 @@ def module_is_offloaded(module):
                     "You are trying to call `.to('cuda')` on a pipeline that has models quantized with `bitsandbytes`. Your current `accelerate` installation does not support it. Please upgrade the installation."
                 )
 
-
         # Display a warning in this case (the operation succeeds but the benefits are lost)
         pipeline_is_offloaded = any(module_is_offloaded(module) for _, module in self.components.items())
         if pipeline_is_offloaded and device_type in ["cuda", "xpu"]:
@@ -1162,11 +1161,9 @@ def enable_model_cpu_offload(self, gpu_id: Optional[int] = None, device: Union[t
                 The PyTorch device type of the accelerator that shall be used in inference. If not specified, it will
                 automatically detect the available accelerator and use.
         """
- 
         self._maybe_raise_error_if_group_offload_active(raise_error=True)
 
-        is_pipeline_device_mapped = hasattr(self, "hf_device_map") and self.hf_device_map is not None and len(self.hf_device_map) > 1
-
+        is_pipeline_device_mapped = self.hf_device_map is not None and len(self.hf_device_map) > 1
         if is_pipeline_device_mapped:
             raise ValueError(
                 "It seems like you have activated a device mapping strategy on the pipeline so calling `enable_model_cpu_offload() isn't allowed. You can call `reset_device_map()` first and then call `enable_model_cpu_offload()`."
@@ -1288,7 +1285,7 @@ def enable_sequential_cpu_offload(self, gpu_id: Optional[int] = None, device: Un
             raise ImportError("`enable_sequential_cpu_offload` requires `accelerate v0.14.0` or higher")
         self.remove_all_hooks()
 
-        is_pipeline_device_mapped = hasattr(self, "hf_device_map") and self.hf_device_map is not None and len(self.hf_device_map) > 1
+        is_pipeline_device_mapped = self.hf_device_map is not None and len(self.hf_device_map) > 1
         if is_pipeline_device_mapped:
             raise ValueError(
                 "It seems like you have activated a device mapping strategy on the pipeline so calling `enable_sequential_cpu_offload() isn't allowed. You can call `reset_device_map()` first and then call `enable_sequential_cpu_offload()`."