qtest.py: Few pylint/style fixes

No actual code changes, just few pylint/style fixes.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-Id: <20170818142613.32394-11-ldoktor@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

scripts/qtest.py

@@ -11,14 +11,11 @@
 # Based on qmp.py.
 #
 
-import errno
 import socket
-import string
 import os
-import subprocess
-import qmp.qmp
 import qemu
 
+
 class QEMUQtestProtocol(object):
     def __init__(self, address, server=False):
         """
@@ -83,8 +80,10 @@ class QEMUQtestMachine(qemu.QEMUMachine):
                  socket_scm_helper=None):
         if name is None:
             name = "qemu-%d" % os.getpid()
-        super(QEMUQtestMachine, self).__init__(binary, args, name=name, test_dir=test_dir,
-                                               socket_scm_helper=socket_scm_helper)
+        super(QEMUQtestMachine,
+              self).__init__(binary, args, name=name, test_dir=test_dir,
+                             socket_scm_helper=socket_scm_helper)
+        self._qtest = None
         self._qtest_path = os.path.join(test_dir, name + "-qtest.sock")
 
     def _base_args(self):