prevent creating a view/leaf param for low rank optimizers w FSDP (#37379)

prevent creating a view/leaf param for low rank optimizers:

Author: winglian

src/transformers/trainer.py

@@ -1363,7 +1363,6 @@ def setup_low_rank_optimizer(
                 and args.optim_target_modules.replace("_", "-") == "all-linear"
             )
 
-            target_params = []
             target_params_names = []
             for module_name, module in model.named_modules():
                 target_module_exists, is_regex = check_target_module_exists(
@@ -1380,12 +1379,12 @@ def setup_low_rank_optimizer(
                 if not target_module_exists and not all_linear:
                     continue
 
-                target_params.append(module.weight)
                 target_params_names.append(module_name + ".weight")
 
-            if len(target_params) == 0:
+            if len(target_params_names) == 0:
                 raise ValueError(f"No target modules found for {optimizer_name} ({args.optim_target_modules}).")
 
+            target_params = [p for n, p in model.named_parameters() if n in target_params_names]
             non_target_params = [p for n, p in model.named_parameters() if n not in target_params_names]
             optim_kwargs.update(optim_args)