Pass code check with pylint=2.4.4 (#1012)

examples/vlanhost.py

@@ -24,14 +24,18 @@ Usage (example uses VLAN ID=1000):
 
 """
 
+from sys import exit  # pylint: disable=redefined-builtin
+
 from mininet.node import Host
 from mininet.topo import Topo
 from mininet.util import quietRun
 from mininet.log import error
 
+
 class VLANHost( Host ):
     "Host connected to VLAN interface"
 
+    # pylint: disable=arguments-differ
     def config( self, vlan=100, **params ):
         """Configure VLANHost according to (optional) parameters:
            vlan: VLAN ID for default interface"""
@@ -54,6 +58,7 @@ class VLANHost( Host ):
 
         return r
 
+
 hosts = { 'vlan': VLANHost }
 
 
@@ -101,6 +106,7 @@ def exampleCustomTags():
     CLI( net )
     net.stop()
 
+
 if __name__ == '__main__':
     import sys
     from functools import partial