staging: comedi: das16: remove unnecessary das16_ai_disable()

The das16_ai_disable() function disables interrupts and the pacer clock. This
function is called by the subdevice (*cancel) operation.

The comedi core will not call a subdevice (*insn_read) operation while an
async command is running due to the s->busy check in parse_insn(). Since all
async commands are terminated by a (*cancel), the das16_ai_disable() is not
necessary in das16_ai_insn_read(). Remove it.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/das16.c

@@ -831,8 +831,6 @@ static int das16_ai_insn_read(struct comedi_device *dev,
 	int ret;
 	int i;
 
-	das16_ai_disable(dev);
-
 	/* set multiplexer */
 	outb(chan | (chan << 4), dev->iobase + DAS16_MUX_REG);