INT 21 - Novell NetWare - PRINT SERVICES - FLUSH LPT CAPTURE
        AH = DFh
        DL = 03h
Return: AL = status
            00h successful
Desc:   this function closes the current capture file for the default LPT
          and starts printing it if it is not a permanent capture file
Notes:  this function is supported by NetWare 4.0+, Advanced NetWare 1.0+, and
          Alloy NTNX; under NTNX, it sends a print break (see INT 17/AH=84h)
        if more data is sent to the LPT port after this call, a new capture
          file will be opeend
SeeAlso: AH=DFh/DL=01h,AH=DFh/DL=02h,AH=DFh/DL=07h