INT 21 - DOS 2+ - IOCTL - GET OUTPUT STATUS

	AX = 4407h
	BX = file handle
Return: CF clear if successful
	    AL = input status
		00h not ready
		FFh ready
	CF set on error
	    AX = error code (01h,05h,06h,0Dh) (see #01680 at AH=59h/BX=0000h)
Notes:	for DOS 2+, files are always ready for output, even if the disk is
	  full or no media is in the drive
	this function was not supported by Digital Research's DOS Plus
SeeAlso: AX=4406h,INT 2F/AX=122Bh