Serial File Descriptor Not Closed When Error Occurs in Serial.__init__ (RDT-912)

[horw]

Describe the bug

  res = None
  try:
      res = func(*args, **kwargs)
      yield res
  finally:
      if res:
          _close_or_terminate(res)

This part of the code only considers close_or_terminate when the object has already been created. However, if the object gets stuck in __init__, the serial file descriptor, for example, will never be closed. A similar bug may occur with other objects as well.

To Reproduce
Steps to reproduce the behavior:

1. Raise any error in the self._start() function of the Serial class.
2. self.proc will never be closed.

Expected behavior
All objects should be processed properly. If there is an exception, any opened resources should be closed.