change xrange() to range()

Python 3 doesn't support xrange, so convert all the usage to range.
This is mostly mechanical, but the conversion tripped a few new
warnings with consider-using-enumerate.

BUG=chromium:980619
TEST=lint is unchanged in chromite
TEST=unittests pass

Change-Id: I9f99e323c3d6d993f40b544cabfcc8697d105f47
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1689012
Tested-by: Mike Frysinger <vapier@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Reviewed-by: David Burger <dburger@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_setup_toolchains.py b/scripts/cros_setup_toolchains.py
index 5f6fc61..ed9fc31 100644
--- a/scripts/cros_setup_toolchains.py
+++ b/scripts/cros_setup_toolchains.py
@@ -1165,10 +1165,10 @@
     if contents[0] == '#!/usr/bin/python2 -S':
       contents[0] = '#!/usr/bin/env python2'
 
-    for num in xrange(len(contents)):
-      if '@CCACHE_DEFAULT@' in contents[num]:
-        assert 'True' in contents[num]
-        contents[num] = contents[num].replace('True', 'False')
+    for num, line in enumerate(contents):
+      if '@CCACHE_DEFAULT@' in line:
+        assert 'True' in line
+        contents[num] = line.replace('True', 'False')
         break
     # Can't update the wrapper in place since it's a hardlink to a file in /.
     os.unlink(sysroot_wrapper)