paycheck: Fix linter errors.

BUG=None
TEST=None

Change-Id: Ife881c35ee090c494307e7f55e3ce0a1a22eb1b1
Reviewed-on: https://chromium-review.googlesource.com/285999
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
diff --git a/scripts/paycheck.py b/scripts/paycheck.py
index 380809e..36edc59 100755
--- a/scripts/paycheck.py
+++ b/scripts/paycheck.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python2
 #
 # Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -6,6 +6,8 @@
 
 """Command-line tool for checking and applying Chrome OS update payloads."""
 
+from __future__ import print_function
+
 import optparse
 import os
 import sys
@@ -34,12 +36,12 @@
 
   Args:
     argv: command-line arguments to parse (excluding the program name)
+
   Returns:
     A tuple (opts, payload, extra_args), where `opts' are the options
     returned by the parser, `payload' is the name of the payload file
     (mandatory argument) and `extra_args' are any additional command-line
     arguments.
-
   """
   parser = optparse.OptionParser(
       usage=('Usage: %prog [OPTION...] PAYLOAD [DST_KERN DST_ROOT '
@@ -165,7 +167,7 @@
     default_meta_sig = args[0] + '.metadata-signature'
     if os.path.isfile(default_meta_sig):
       opts.meta_sig = default_meta_sig
-      print >> sys.stderr, 'Using default metadata signature', opts.meta_sig
+      print('Using default metadata signature', opts.meta_sig, file=sys.stderr)
 
   return opts, args[0], args[1:]