Fix nodesetboot argument parsing

confluent_client/bin/nodesetboot

@@ -53,8 +53,8 @@ except IndexError:
     argparser.print_help()
     sys.exit(1)
 bootdev = None
-if len(sys.argv) > 2:
-    bootdev = sys.argv[2]
+if len(args) > 1:
+    bootdev = args[1]
     if bootdev in ('net', 'pxe'):
         bootdev = 'network'
 session = client.Command()
@@ -65,4 +65,4 @@ else:
     bootmode = 'uefi'
 sys.exit(session.simple_noderange_command(noderange, '/boot/nextdevice', bootdev,
                                      bootmode=bootmode,
-                                     persistent=options.persist))
+                                     persistent=options.persist))