use get_tensor in safe_open (#1696)

Author: twaka

vllm/model_executor/weight_utils.py

@@ -243,8 +243,8 @@ def hf_model_weights_iterator(
         for st_file in hf_weights_files:
             with safe_open(st_file, framework="pt") as f:
                 for name in f.keys():
-                    param = f.get_slice(name)
-                    yield name, convert_pyslice_to_tensor(param)
+                    param = f.get_tensor(name)
+                    yield name, param
     else:
         for bin_file in hf_weights_files:
             state = torch.load(bin_file, map_location="cpu")
@@ -265,12 +265,7 @@ def convert_pyslice_to_tensor(x: Any) -> torch.Tensor:
     tensor first.
     """
     if not isinstance(x, torch.Tensor):
-        try:
-            x = x[:]
-        except IndexError:
-            # IndexError happens when the tensor is empty.
-            # transformer.h.0.attn.masked_bias is empty in some gpt2 models.
-            return torch.Tensor()
+        x = x[:]
     return x