Replaced example topologies __init__ with build

examples/multilink.py

@@ -21,9 +21,7 @@ def runMultiLink():
 class simpleMultiLinkTopo( Topo ):
     "Simple topology with multiple links"
 
-    def __init__( self, n, **kwargs ):
-        Topo.__init__( self, **kwargs )
-
+    def build( self, n, **kwargs ):
         h1, h2 = self.addHost( 'h1' ), self.addHost( 'h2' )
         s1 = self.addSwitch( 's1' )