data duplicate when setting num_works > 1 with streaming data
## Describe the bug
The data is repeated num_works times when we load_dataset with streaming and set num_works > 1 when construct dataloader

## Steps to reproduce the bug
```python
# Sample code to reproduce the bug
import pandas as pd
import numpy as np
import os

from datasets import load_dataset
from torch.utils.data import DataLoader
from tqdm import tqdm
import shutil

NUM_OF_USER = 1000000
NUM_OF_ACTION = 50000
NUM_OF_SEQUENCE = 10000
NUM_OF_FILES = 32
NUM_OF_WORKERS = 16

if __name__ == "__main__":
    shutil.rmtree("./dataset")
    for i in range(NUM_OF_FILES):
        sequence_data = pd.DataFrame(
            {
                "imei": np.random.randint(1, NUM_OF_USER, size=NUM_OF_SEQUENCE),
                "sequence": np.random.randint(1, NUM_OF_ACTION, size=NUM_OF_SEQUENCE)
            }
        )

        if not os.path.exists("./dataset"):
            os.makedirs("./dataset")

        sequence_data.to_csv(f"./dataset/sequence_data_{i}.csv",
                            
 index=False)

    dataset = load_dataset("csv",
                           data_files=[os.path.join("./dataset",file) for file in os.listdir("./dataset") if file.endswith(".csv")],
                           split="train",
                           streaming=True).with_format("torch")
    data_loader = DataLoader(dataset,
                             batch_size=1024,
                             num_workers=NUM_OF_WORKERS)
    
    result = pd.DataFrame()
    for i, batch in tqdm(enumerate(data_loader)):
        result = pd.concat([result, 
                           pd.DataFrame(batch)],
                           axis=0)
    result.to_csv(f"num_work_{NUM_OF_WORKERS}.csv", index=False)

```

## Expected results
data do not duplicate 

## Actual results
data duplicate NUM_OF_WORKERS = 16 
![image](https://user-images.githubusercontent.com/16486492/145748707-9d2df25b-2f4f-4d7b-a83e-242be4fc8934.png)


## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version:datasets==1.14.0
- Platform:transformers==4.11.3
- Python version:3.8
- PyArrow version:
