Pass code check with pylint=2.4.4 (#1012)

examples/multipoll.py

@@ -6,15 +6,15 @@ monitoring them
 """
 
 
+from time import time
+from select import poll, POLLIN
+from subprocess import Popen, PIPE
+
 from mininet.topo import SingleSwitchTopo
 from mininet.net import Mininet
 from mininet.log import info, setLogLevel
 from mininet.util import decode
 
-from time import time
-from select import poll, POLLIN
-from subprocess import Popen, PIPE
-
 
 def monitorFiles( outfiles, seconds, timeoutms ):
     "Monitor set of files and return [(host, line)...]"