fixed error

implementation/mininet_controller.py

@@ -607,7 +607,8 @@ def run(topology, test=None, limit=None, delay=None, shortcut=False):
 
     # if we want to create a timed failure (maybe while pinging), we can use a timer
     # router2_failure = Timer(15, introduce_failure(net["r2"], "r2-eth3"))
-
+    global packet_counter_initialized
+    packet_counter_initialized = False
     net.start()
     # CLI(net)
     n = 1
@@ -707,8 +708,6 @@ if __name__ == '__main__':
         run(args.topo, args.test, bw_limit, delay, use_shortcut)
         sleep(1)
         use_shortcut = True
-        global packet_counter_initialized
-        packet_counter_initialized = False
         run(args.topo, args.test, bw_limit, delay, use_shortcut)
     else:
         run(args.topo, args.test, bw_limit, delay, use_shortcut)