[Fix] Fix the unit test of correlation op (#1659)

tests/test_ops/test_correlation.py

@@ -30,10 +30,13 @@ class TestCorrelation:
         out = layer(input1, input2)
         out.backward(torch.ones_like(out))
 
-        gt_out = torch.tensor(_gt_out, dtype=dtype)
-        assert_equal_tensor(out.cpu(), gt_out)
-        assert_equal_tensor(input1.grad.detach().cpu(), input2.cpu())
-        assert_equal_tensor(input2.grad.detach().cpu(), input1.cpu())
+        # `eq_cpu` is not implemented for 'Half' in torch1.5.0,
+        # so we need to make a comparison for cuda tensor
+        # rather than cpu tensor
+        gt_out = torch.tensor(_gt_out, dtype=dtype).cuda()
+        assert_equal_tensor(out, gt_out)
+        assert_equal_tensor(input1.grad.detach(), input2)
+        assert_equal_tensor(input2.grad.detach(), input1)
 
     @pytest.mark.skipif(
         not torch.cuda.is_available(), reason='requires CUDA support')