message: fix ptr of SEEK_END
diff: @@ -125,7 +125,7 @@ static int mmap_stream_seek(php_stream *stream, off_t offset, int whence, off_t
  *newoffset = (off_t) -1;
  return -1;
  }
  - res->ptr += offset;
  + res->ptr = res->memory + res->size + offset;
  *newoffset = res->ptr - res->memory;
  return 0;
  default:
  