test error from test_testtimeaugmentation

[wyli]

Describe the bug
from nightly build, probably a torch 1.5 only issue:

======================================================================
ERROR: test_requires_meta_dict (tests.test_testtimeaugmentation.TestTestTimeAugmentation)
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Traceback (most recent call last):
  File "/home/jenkins/agent/workspace/Monai-pytorch-versions/monai/data/utils.py", line 271, in list_data_collate
    ret[k] = default_collate([d[k] for d in data])
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 79, in default_collate
    return [default_collate(samples) for samples in transposed]
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 79, in <listcomp>
    return [default_collate(samples) for samples in transposed]
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 74, in default_collate
    return {key: default_collate([d[key] for d in batch]) for key in elem}
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 74, in <dictcomp>
    return {key: default_collate([d[key] for d in batch]) for key in elem}
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 74, in default_collate
    return {key: default_collate([d[key] for d in batch]) for key in elem}
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 74, in <dictcomp>
    return {key: default_collate([d[key] for d in batch]) for key in elem}
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 64, in default_collate
    return default_collate([torch.as_tensor(b) for b in batch])
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/collate.py", line 55, in default_collate
    return torch.stack(batch, 0, out=out)
RuntimeError: Expected object of scalar type double but got scalar type float for sequence element 1.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/jenkins/agent/workspace/Monai-pytorch-versions/tests/test_testtimeaugmentation.py", line 155, in test_requires_meta_dict
    tta(self.get_data(1, (20, 20), include_label=False))
  File "/home/jenkins/agent/workspace/Monai-pytorch-versions/monai/data/test_time_augmentation.py", line 173, in __call__
    for batch_data in tqdm(dl) if has_tqdm and self.progress else dl:
  File "/opt/conda/lib/python3.6/site-packages/tqdm/std.py", line 1180, in __iter__
    for obj in iterable:
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/dataloader.py", line 345, in __next__
    data = self._next_data()
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/dataloader.py", line 385, in _next_data
    data = self._dataset_fetcher.fetch(index)  # may raise StopIteration
  File "/opt/conda/lib/python3.6/site-packages/torch/utils/data/_utils/fetch.py", line 47, in fetch
    return self.collate_fn(data)
  File "/home/jenkins/agent/workspace/Monai-pytorch-versions/monai/data/utils.py", line 446, in pad_list_data_collate
    return PadListDataCollate(method=method, mode=mode, **np_kwargs)(batch)
  File "/home/jenkins/agent/workspace/Monai-pytorch-versions/monai/transforms/croppad/batch.py", line 119, in __call__
    return list_data_collate(batch)
  File "/home/jenkins/agent/workspace/Monai-pytorch-versions/monai/data/utils.py", line 284, in list_data_collate
    raise RuntimeError(re_str) from re
RuntimeError: Expected object of scalar type double but got scalar type float for sequence element 1.

----------------------------------------------------------------------

================================
Printing MONAI config...
================================
MONAI version: 0.7.0+71.g7da61305
Numpy version: 1.18.1
Pytorch version: 1.5.1
MONAI flags: HAS_EXT = True, USE_COMPILED = True
MONAI rev id: 7da613056fec29ee764857a417d4cca61f07986b

Optional dependencies:
Pytorch Ignite version: 0.4.6
Nibabel version: 3.2.1
scikit-image version: 0.15.0
Pillow version: 8.4.0
Tensorboard version: 2.1.0
gdown version: 4.2.0
TorchVision version: 0.6.1
tqdm version: 4.62.3
lmdb version: 0.98
psutil version: 5.6.7
pandas version: 0.24.2
einops version: 0.3.2
transformers version: 4.11.3
mlflow version: 1.20.2

[wyli]

this one should always use the original meta info:

MONAI/monai/data/test_time_augmentation.py

Line 162 in 536e056

data_in = [d] * num_examples

the issue becomes obvious after https://github.com/Project-MONAI/MONAI/pull/3166/files