Since the function doesn't call |BN_CTX_get|, it doesn't need to call |BN_CTX_start|/|BN_CTX_end|. Change-Id: I6cb954d3fee2959bdbc81b9b97abc52bb6f7704c Reviewed-on: https://boringssl-review.googlesource.com/7469 Reviewed-by: David Benjamin <davidben@google.com>kris/onging/CECPQ3_patch15