tests: fix test for mouse+keyboard devices

On fc23-based dom0 a single mouse+keyboard device is listed as two
devices (one in "pointer" section, other as "keyboard"). This confuses
'xinput list', so add explicit request for device type.

QubesOS/qubes-issues#1618

qubesinputproxy/tests.py

@@ -178,6 +178,9 @@ def find_device_and_start_listener(self, expected_name=None):
         self.assertIsNotNone(device_id,
             "Devive '{}' not found".format(expected_name))
 
+        # terminate old listener if there was one
+        if hasattr(self, 'event_listener'):
+            self.event_listener.terminate()
         self.event_listener = subprocess.Popen(
             ['xinput', 'test-xi2', '--root', device_id],
             stdout=subprocess.PIPE)
@@ -261,7 +264,8 @@ def test_040_mouse_keyboard(self):
         self.qrexec_policy('qubes.InputMouse', self.vm.name, 'dom0')
         self.qrexec_policy('qubes.InputKeyboard', self.vm.name, 'dom0')
         self.setUpDevice(mouse_events + keyboard_events)
-        self.find_device_and_start_listener()
+        self.find_device_and_start_listener(
+            'pointer:{}: {}'.format(self.vm.name, 'Test input device'))
         self.emit_event('REL_X', 1)
         self.emit_event('REL_X', 1)
         self.emit_event('REL_Y', 1)
@@ -275,6 +279,9 @@ def test_040_mouse_keyboard(self):
         self.assertEvent(['RawButtonPress', '1', {}])
         self.assertEvent(['RawButtonRelease', '1', {}])
 
+        self.find_device_and_start_listener(
+            'keyboard:{}: {}'.format(self.vm.name, 'Test input device'))
+
         self.emit_click('KEY_A')
         self.emit_click('KEY_B')
         self.emit_click('KEY_C')