This reverts commits 36ca21415a and
7b668a873e. We believe that we need to
update ASAN to be aware of getrandom before we can use it. Otherwise it
believes that the memory with the entropy from this syscall is
uninitialised.

Change-Id: I1ea1c4d3038b3b2cd080be23d7d8b60fc0c83df2
Reviewed-on: https://boringssl-review.googlesource.com/12901
Reviewed-by: Adam Langley <alangley@gmail.com>
Commit-Queue: Adam Langley <alangley@gmail.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>