Enable fewer EV_KEY events in InputDevice

Fixes #166

Starting with systemd 247 (?), desktop environments fail to recognize
the virtual input device if it has too many enabled libinput events.

It seems like KEY_ROTATE_LOCK_TOGGLE as the highest enabled event is a
good limit. This is the highest evdev event mapped by xkb, so the
usefulness higher events is limited, anyways.

src/logid/InputDevice.cpp

@@ -45,7 +45,9 @@ InputDevice::InputDevice(const char* name)
 
     ///TODO: Is it really a good idea to enable all events?
     libevdev_enable_event_type(device, EV_KEY);
-    for(unsigned int i = 0; i < KEY_CNT; i++)
+    // KEY_ROTATE_LOCK_TOGGLE is the highest key mapped by
+    // /usr/share/X11/xkb/keycodes/evdev
+    for(unsigned int i = 0; i <= KEY_ROTATE_LOCK_TOGGLE; i++)
         libevdev_enable_event_code(device, EV_KEY, i, nullptr);
     libevdev_enable_event_type(device, EV_REL);
     for(unsigned int i = 0; i < REL_CNT; i++)