Fix format errors found by autopep8.

Most of them are whitespace error.

BUG=None
TEST=make test

Change-Id: I3850dbf1ecc567e8c4bf1d00aba94f844328cbc3
Reviewed-on: https://chromium-review.googlesource.com/1218307
Commit-Ready: Pi-Hsun Shih <pihsun@chromium.org>
Tested-by: Pi-Hsun Shih <pihsun@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
diff --git a/py/tools/ovl.py b/py/tools/ovl.py
index 5d372fb..3a7b435 100755
--- a/py/tools/ovl.py
+++ b/py/tools/ovl.py
@@ -1255,7 +1255,7 @@
     self.CheckClient()
 
     @AutoRetry('pull', _RETRY_TIMES)
-    def _pull(src, dst, ftype, perm=0644, link=None):
+    def _pull(src, dst, ftype, perm=0o644, link=None):
       try:
         os.makedirs(os.path.dirname(dst))
       except Exception: