[Metal] Add pin_memory check in empty_strided (#47228)

Summary:
Pull Request resolved: #47228

Add the false checking if pin_memory has been specified to `False`
ghstack-source-id: 115715087

Test Plan:
- CircleCI
- Sandcastle

Reviewed By: IvanKobzarev

Differential Revision: D24690472

fbshipit-source-id: c65fc494fcd7b0b409a80c86e108a029ca7fd71e

aten/src/ATen/native/metal/MetalAten.mm

@@ -91,7 +91,7 @@ Tensor empty(
     optional<Device> device,
     optional<bool> pin_memory) {
   TORCH_CHECK(
-      !pin_memory.has_value(),
+      !pin_memory.has_value() || !pin_memory.value(),
       "'pin_memory' argument is incompatible with Metal tensor");
   MetalTensor mt{size.vec(), stride.vec()};
   return MetalTensor::toTensor(