IOMX: Add buffer range check to emptyBuffer

    Mutex::Autolock autoLock(mLock);

    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer);

    // rangeLength and rangeOffset must be a subset of the allocated data in the buffer.

    // corner case: we permit rangeOffset == end-of-buffer with rangeLength == 0.

    if (rangeOffset > header->nAllocLen

            || rangeLength > header->nAllocLen - rangeOffset) {

        return BAD_VALUE;

    }

    header->nFilledLen = rangeLength;

    header->nOffset = rangeOffset;