In addition, make use of bssl::ScopedEVP_MD_CTX in |SpeedHashChunk|,
otherwise the ctx doesn't get destroyed on failure.
Change-Id: I5828080cb9f4eb7c77cc2ff185d9aa8135311385
Reviewed-on: https://boringssl-review.googlesource.com/27464
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>