tweak octal numbers style to work with python-3

BUG=None
TEST=`./run_tests` passed

Change-Id: Ife102f80efdb5e040dc2ba96ac7aa4ee3f7a6c75
Reviewed-on: https://chromium-review.googlesource.com/173729
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_setup_toolchains.py b/scripts/cros_setup_toolchains.py
index 91089d2..81619fc 100644
--- a/scripts/cros_setup_toolchains.py
+++ b/scripts/cros_setup_toolchains.py
@@ -559,7 +559,7 @@
   else:
     osutils.SafeMakedirs(os.path.dirname(root_wrapper))
   osutils.WriteFile(root_wrapper, wrapper)
-  os.chmod(root_wrapper, 0755)
+  os.chmod(root_wrapper, 0o755)
 
 
 def FileIsCrosSdkElf(elf):
@@ -810,7 +810,7 @@
   # Can't update the wrapper in place since it's a hardlink to a file in /.
   os.unlink(sysroot_wrapper)
   osutils.WriteFile(sysroot_wrapper, '\n'.join(contents))
-  os.chmod(sysroot_wrapper, 0755)
+  os.chmod(sysroot_wrapper, 0o755)
 
 
 def _ProcessDistroCleanups(target, output_dir):