Fix setting of memory fraction in test_garbage_collect_expandable (#1… (#2697)

Fixes SWDEV-551121

test_cuda.py::TestCudaOptimsCUDA::test_grad_scaling_autocast_fused_optimizers_AdamW_cuda_float32

test_cuda.py::TestCudaOptimsCUDA::test_grad_scaling_autocast_fused_optimizers_Adam_cuda_float32

test_cuda.py::TestCudaOptimsCUDA::test_grad_scaling_autocast_fused_optimizers_SGD_cuda_float32

Co-authored-by: rraminen <[email protected]>

Author: BLOrange-AMD

test/test_cuda.py

@@ -4475,7 +4475,7 @@ def alloc(n):
             # expandable_segment blocks can be in the free list when this is called.
             alloc(80)
         finally:
-            orig = torch.cuda.get_per_process_memory_fraction(0)
+            torch.cuda.memory.set_per_process_memory_fraction(orig)
 
     def test_allocator_settings(self):
         def power2_div(size, div_factor):