tls_set_ssl_errorx
tls_set_ssl_errorx(ctx, "%s failed: %s", prefix, errstr);
tls_set_ssl_errorx(ctx, "%s failed: %s", prefix, errstr);
tls_set_ssl_errorx(ctx, "%s failed (%d)", prefix, ssl_err);
int tls_set_ssl_errorx(struct tls *ctx, const char *fmt, ...)