List the number of ports found in debug mode at startup

Change-Id: I1841ff850eb9d9409eb9bddc4bbb21fc49539f6b
diff --git a/drivers/CiscoCatalyst.py b/drivers/CiscoCatalyst.py
index d3cea59..405b3d2 100644
--- a/drivers/CiscoCatalyst.py
+++ b/drivers/CiscoCatalyst.py
@@ -544,6 +544,7 @@
                         # marked as "routed"
                     if not match1 and not match2:
                         interfaces.append(interface)
+            logging.debug("  found %d ports on the switch", len(interfaces))
             return interfaces
 
         except PExpectError: