fix bugs found by pylint
diff --git a/src/python/oftest/packet.py b/src/python/oftest/packet.py
index 67dffb2..1b43091 100644
--- a/src/python/oftest/packet.py
+++ b/src/python/oftest/packet.py
@@ -4,6 +4,7 @@
 """
 Wrap scapy to satisfy pylint
 """
+import sys
 
 try:
     import scapy.layers.l2