Fix LGTM alert

Author: Jostar Yang

platform/broadcom/sonic-platform-modules-accton/as5835-54t/utils/accton_as5835_54t_pddf_monitor.py

@@ -26,8 +26,7 @@
     import sys, getopt
     import logging
     import logging.config
-    import types
-    import time  # this is only being used as part of the example
+    import time
     import signal
     from sonic_platform import platform
 except ImportError as e:
@@ -235,4 +234,4 @@ def main(argv):
         time.sleep(10)
 
 if __name__ == '__main__':
-    main(sys.argv[1:])
+    main(sys.argv[1:])