self.logfile, not logfile. Gah

Change-Id: I1b32ad8885b5782966390e6baccfd74af286a158
diff --git a/drivers/CiscoSX300.py b/drivers/CiscoSX300.py
index d551bbb..ce00187 100644
--- a/drivers/CiscoSX300.py
+++ b/drivers/CiscoSX300.py
@@ -40,7 +40,7 @@
 
     def __init__(self, switch_hostname, switch_telnetport=23, debug = False):
         if debug:
-            logfile = sys.stderr
+            self.logfile = sys.stderr
         self.exec_string = "/usr/bin/telnet %s %d" % (switch_hostname, switch_telnetport)
 
     ################################