Use PLOG() for failed system calls, so we see errno.

                        if (event.events & EPOLLIN) {

                            int rc = TEMP_FAILURE_RETRY(read(framework_fd_.get(), buf, sizeof(buf)));

                            if (rc == -1) {

                                LOG(FATAL) << "adbd_auth: failed to read from framework fd";

                                PLOG(FATAL) << "adbd_auth: failed to read from framework fd";

                            } else if (rc == 0) {

                                LOG(INFO) << "adbd_auth: hit EOF on framework fd";

                                std::lock_guard<std::mutex> lock(mutex_);