Fix bug preventing packet in/out from working

Bug resulted in an unhandled deferred killing the callback
preventing the packet from being removed from the queue

Change-Id: I8fb97699de24b2803df6c74d03ea27f7fe8c59ac
diff --git a/python/ofagent/grpc_client.py b/python/ofagent/grpc_client.py
index 7f6d274..42e8510 100755
--- a/python/ofagent/grpc_client.py
+++ b/python/ofagent/grpc_client.py
@@ -172,13 +172,13 @@
             packet_in = yield self.packet_in_queue.get()
             device_id = packet_in.id
             ofp_packet_in = packet_in.packet_in
-            self.log.debug('grpc client to send packet-in')
+            log.debug('grpc client to send packet-in')
             self.connection_manager.forward_packet_in(device_id, ofp_packet_in)
             if self.stopped:
                 break
 
     def send_packet_out(self, device_id, packet_out):
-        self.log.debug('grpc client to send packet-out')
+        log.debug('grpc client to send packet-out')
         packet_out = PacketOut(id=device_id, packet_out=packet_out)
         self.packet_out_queue.put(packet_out)