Slightly improve performance in engines/utils.py (#8747)

### Description
This change probably improves performance slightly (unforetunately, I
don't have a local instance of MONAI installed in order to test this,
but I'm pretty sure from looking at the code that using [], {} and
kwargs_[k] = _get_data(v) should be semantically the same and probably
slightly better in performance, see also #1423 (credits to @de-sh for
the nice fix 👍 ) where at least [] and {} were changed as a refactoring
and kwargs_[k] = _get_data(v) just seems better to me becuase I think
that this saves some time due to dictionary lookups and temporary
objects, but I'm not quite sure because it wasn't tested, so please
correct me if I'm mistaken).

A few sentences describing the changes proposed in this pull request.

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [ ] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [ ] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated, tested `make html` command in the `docs/`
folder.

---------

Signed-off-by: Benedikt Johannes <benedikt.johannes.hofer@gmail.com>

Author: benediktjohannes

monai/engines/utils.py

@@ -219,8 +219,8 @@ def __call__(
         `kwargs` supports other args for `Tensor.to()` API.
         """
         image, label = default_prepare_batch(batchdata, device, non_blocking, **kwargs)
-        args_ = list()
-        kwargs_ = dict()
+        args_ = []
+        kwargs_ = {}
 
         def _get_data(key: str) -> torch.Tensor:
             data = batchdata[key]