Fix lint (#7408)

test/test_image.py

@@ -368,10 +368,10 @@ def test_decode_jpeg_cuda(mode, img_path, scripted):
     # Some difference expected between jpeg implementations
     assert (img.float() - img_nvjpeg.cpu().float()).abs().mean() < 2
 
+
 @needs_cuda
 def test_decode_image_cuda_raises():
     data = torch.randint(0, 127, size=(255,), device="cuda", dtype=torch.uint8)
-    exception_raised = True
     with pytest.raises(RuntimeError):
         decode_image(data)