Get statistics

        Entry:
          AH = 24h
          BX = handle
        Return:
          CF set on error
            DH = error code
          CF clear if successful
            DS:SI -> statistics (see below)

        Format of statistics:

        Offset  Size    Description
         00h    DWORD   packets in
         04h    DWORD   packets out
         08h    DWORD   bytes in
         0Ch    DWORD   bytes out
         10h    DWORD   errors in
         14h    DWORD   errors out
         18h    DWORD   packets dropped