python/machine: disable warning for Popen in _launch()

We handle this resource rather meticulously in
shutdown/kill/wait/__exit__ et al, through the laborious mechanisms in
_do_shutdown().

Quiet this pylint warning here.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-id: 20210527211715.394144-7-jsnow@redhat.com
Message-id: 20210517184808.3562549-7-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

python/qemu/machine.py

@@ -405,6 +405,9 @@ def _launch(self) -> None:
                   self._args)
         )
         LOG.debug('VM launch command: %r', ' '.join(self._qemu_full_args))
+
+        # Cleaning up of this subprocess is guaranteed by _do_shutdown.
+        # pylint: disable=consider-using-with
         self._popen = subprocess.Popen(self._qemu_full_args,
                                        stdin=subprocess.DEVNULL,
                                        stdout=self._qemu_log_file,