PosixPath fixes to code snippets

hpvm/projects/torch2hpvm/README.md

@@ -26,7 +26,7 @@ First, prepare 2 datasets for autotuning and testing.
 
 ```python
 from torch2hpvm import BinDataset
-from pathlib import Path
+from pathlib import Path, PosixPath
 
 data_dir = Path(__file__).parent / "model_params/resnet18_cifar10"
 dataset_shape = 5000, 3, 32, 32
@@ -52,7 +52,7 @@ from torch.nn import Module
 import dnn  # Defined at `hpvm/test/dnn_benchmarks/pytorch`
 
 model: Module = dnn.ResNet18()
-checkpoint = Path(__file__).parent / "model_params/resnet18_cifar10.pth.tar"
+checkpoint = Path(__file__).parent.absolute()  /  PosixPath("../model_params/resnet18_cifar10.pth.tar")
 model.load_state_dict(torch.load(checkpoint))
 ```