Adding "--" to argment list may change the argument of the program started by `mprof run`.

Consider a program called `test.py` that may have an option `-number -1`. Command
```bash
mprof run python test.py -number -1
```
will pass `-number -- -1` to `test.py`, i.e. `test.py` is started by
```bash
python test.py -number -- -1
```

It seems that the `run` action doesn't need `--` to distinguish the parameters.