Switch markers from BORINGSSL_201510 to OPENSSL_IS_BORINGSSL
Switch markers from BORINGSSL_201510 to OPENSSL_IS_BORINGSSL

BoringSSL changed to use a more sane data type, but OpenSSL is still
stuck with int.

Change-Id: I9ac0eb18d98ed672565eebe789664ef5bae5d383

google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt