Fix incorrect filenames in vllm_compile_cache.py

Test Plan:
- I ran `vllm serve meta-llama/Llama-3.2-1B-Instruct` locally and
  verified that vllm_compile_cache.py's filenames look like the following:

```
/home/rzou/.cache/vllm/torch_compile_cache/a785fdbf18/rank_0_0/inductor_cache/w2/cw22szhsitonk3z4ek
x476g3hzaet3vy5qmsoewpx3kgbokhcob2.py')}
```

Signed-off-by: rzou <zou3519@gmail.com>

Signed-off-by:  <zou3519@gmail.com>

Author: zou3519

vllm/compilation/compiler_interface.py

@@ -228,7 +228,11 @@ def hijacked_compile_fx_inner(*args, **kwargs):
                 inductor_compiled_graph = output
                 if inductor_compiled_graph is not None:
                     nonlocal file_path
-                    file_path = inductor_compiled_graph.current_callable.__code__.co_filename  # noqa
+                    # the current_callable captures two things, the inputs_idx
+                    # (0) and the function (1) from which we are going to pull
+                    # the filename from.
+                    file_path = inductor_compiled_graph.current_callable.__closure__[  # noqa
+                        1].cell_contents.__code__.co_filename  # noqa
                     hash_str = inductor_compiled_graph._fx_graph_cache_key
                 return output