clang package script: fix more fallout from e99ac7b11ab89

Need to import the platform module, and need to not shadow it with
a local variable too.

Bug: 1103322
Change-Id: I613a77e7a5a9f23d24a25d458b32db4f952bad77
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2800173
Reviewed-by: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#868587}
GitOrigin-RevId: 0a334e226413dfe48fefed80568e93b134ecb380
1 file changed