Delete tap9 for CE

In the future, we should probably not hardwire this,
or should at least make it a constant!!

mininet/clean.py

@@ -92,6 +92,10 @@ def cleanup( cls):
             if link:
                 sh( "ip link del " + link )
 
+        if 'tap9' in sh( 'ip link show' ):
+            info( "*** Removing tap9 - assuming it's from cluster edition\n" )
+            sh( 'ip link del tap9' )
+        
         info( "*** Killing stale mininet node processes\n" )
         killprocs( 'mininet:' )