message: imgcodecs(pxm): fix memcpy size
diff: @@ -333,7 +333,7 @@ bool PxMDecoder::readData( Mat& img )
  }
  }
  else
  - memcpy( data, src, CV_ELEM_SIZE1(m_type)*m_width);
  + memcpy(data, src, img.elemSize1()*m_width);
  }
  else
  {
  