[Fuchsia] Fix update-sdk.py not to re-download the same SDK.

The script was looking in the wrong place for the legacy SDK files.

Bug: 977018, 989335
Change-Id: Ibd7d3f8e35633af579c27f282e47487a8fc20f23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1726959
Auto-Submit: Wez <wez@chromium.org>
Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682877}
1 file changed