Fix some unsigned long cipher masks. 107db5804733944a474747007dd1b180405849f9 missed a few. Change-Id: Ib1c7e85e7de7e26888be17d3b644d856b134f76e Reviewed-on: https://boringssl-review.googlesource.com/4400 Reviewed-by: Adam Langley <agl@google.com>