|EVP_PKEY_up_ref| was a BoringSSL addition to OpenSSL The next major,
public OpenSSL release will include it, but it'll return 0/1 rather than
the object being referenced.

This change updates Chromium to expect that function signature (in a
backwards compatible way). Once all callers have been updated likewise,
BoringSSL will align this function with upstream OpenSSL.

BUG=none

Review-Url: https://codereview.chromium.org/2113143004
Cr-Commit-Position: refs/heads/master@{#405192}