[Symmetric memory] set handle type for ROCm (pytorch#161741)

Fixes pytorch#161722

Pull Request resolved: pytorch#161741
Approved by: https://github.com/kwen2501

Author: ngimel

torch/csrc/distributed/c10d/symm_mem/CUDASymmetricMemory.cu

@@ -454,6 +454,7 @@ void* CUDASymmetricMemoryAllocator::alloc(
   C10_CUDA_DRIVER_CHECK(status);
 
 #elif defined(USE_ROCM)
+  handle_type_ = Expandable_Segments_Handle_Type::POSIX_FD;
   hipMemAllocationProp prop = {};
   prop.type = hipMemAllocationTypePinned;
   prop.location.type = hipMemLocationTypeDevice;