docs(tensorrt/utils.py): update docstring

mmdeploy/backend/tensorrt/utils.py

@@ -42,7 +42,7 @@ def load(path: str) -> trt.ICudaEngine:
 
 
 def search_cuda_version() -> str:
- """try import torch.version.cuda, then try use cmd.
+ """try cmd to get cuda version, then try `torch.cuda`
 
  Returns:
  str: cuda version, for example 10.2