Android is now using Ninja so it doesn't spew so much to the terminal
and thus any warnings in BoringSSL (which builds really early in the
process) and much more obvious.
Thus this change fixes a few warnings that appear in the Android build.
Change-Id: Id255ace90fece772a1c3a718c877559ce920b960
Reviewed-on: https://boringssl-review.googlesource.com/6400
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>