Merge "libmedia: Preserve futex return status in client obtainBuffer" am: 72536447

            errno = 0;

            (void) syscall(__NR_futex, &cblk->mFutex,

                    mClientInServer ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT, old & ~CBLK_FUTEX_WAKE, ts);

            status_t error = errno; // clock_gettime can affect errno

            // update total elapsed time spent waiting

            if (measure) {

                struct timespec after;

                before = after;

                beforeIsValid = true;

            }

            switch (errno) {

            switch (error) {

            case 0:            // normal wakeup by server, or by binderDied()

            case EWOULDBLOCK:  // benign race condition with server

            case EINTR:        // wait was interrupted by signal or other spurious wakeup

                // FIXME these error/non-0 status are being dropped

                break;

            default:

                status = errno;

                status = error;

                ALOGE("%s unexpected error %s", __func__, strerror(status));

                goto end;

            }