Return proper default for unknown values in pInfo->device_control.

Signed-off-by: Terry Lambert <tlambert@chromium.org>
Reviewed-by: Stephane Marchesin <marcheu@chromium.org>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/void.c

@@ -171,6 +171,9 @@ xf86VoidControlProc(DeviceIntPtr device, int what)
     case DEVICE_CLOSE:
 	device->public.on = FALSE;
 	break;
+
+    default:
+	return BadValue;
     }
     return Success;
 }