refactor: nit change for get_parameters_from_modules (code debt) (#3815)

* refactor: nit change for get_parameters_from_modules

Signed-off-by: Mehant Kammakomati <[email protected]>

* fix: quality check

Signed-off-by: Mehant Kammakomati <[email protected]>

---------

Signed-off-by: Mehant Kammakomati <[email protected]>

Author: kmehant

src/accelerate/utils/fsdp_utils.py

@@ -630,11 +630,8 @@ def fsdp2_prepare_model(accelerator, model: torch.nn.Module) -> torch.nn.Module:
         # `fully_shard` doesn't accept `None` in case of `MixedPrecisionPolicy`
         "mp_policy": fsdp2_plugin.mixed_precision_policy or MixedPrecisionPolicy(),
         "mesh": mesh[tuple(accelerator.parallelism_config.fsdp_dim_names)] if mesh is not None else None,
+        "ignored_params": get_parameters_from_modules(fsdp2_plugin.ignored_modules, model, accelerator.device),
     }
-    if fsdp2_plugin.ignored_modules is not None:
-        fsdp2_kwargs["ignored_params"] = get_parameters_from_modules(
-            fsdp2_plugin.ignored_modules, model, accelerator.device
-        )
 
     model_has_params4bit = False
     for name, param in model.named_parameters():
@@ -808,10 +805,10 @@ def get_parameters_from_modules(
         modules (`Union[Iterable[torch.nn.Module], str]`): List of modules
 
     Returns:
-        `List[torch.nn.Parameter]`: List of parameters
+        `set[torch.nn.Parameter]`: List of parameters
     """
     if modules is None:
-        return None
+        return set()
     parameters = []
     # code taken from accelerate while preparing kwargs for FSDP
     if isinstance(modules, str):