Silence CUDA graph tree cuda warning (pytorch#103636)

Fixes ``` /data/home/marksaroufim/miniconda/envs/saf/lib/python3.8/site-packages/torch/_inductor/cudagraph_trees.py:85: UserWarning: 'has_cuda' is deprecated, please use 'torch.backends.cuda.is_built()' if torch.has_cuda: Traceback (most recent call last): ``` Pull Request resolved: pytorch#103636 Approved by: https://github.com/eellison

Author: msaroufim

torch/_inductor/cudagraph_trees.py

@@ -82,7 +82,7 @@
 StorageDataPtr = int
 NBytes = int
 
-if torch.has_cuda:
+if torch.backends.cuda.is_built():
  from torch._C import (
  _cuda_CUDAAllocator_AllocatorState as AllocatorState,
  _set_cached_tensors_enabled as _set_cached_tensors_enabled,