staging: comedi: icp_multi: correct insn_bits returned data for DO

For some unfathomable reason, the Comedi `insn_bits` handler for the
digital output subdevice (`icp_multi_insn_bits_do()`) writes the digital
output register and reads back the unrelated digital input register.
Read back the current state of the outputs (held in `s->state`) instead.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/icp_multi.c

@@ -53,7 +53,7 @@ Configuration options: not applicable, uses PCI auto config
 #define ICP_MULTI_AI		2	/* R:   Analogue input data */
 #define ICP_MULTI_DAC_CSR	4	/* R/W: DAC command/status register */
 #define ICP_MULTI_AO		6	/* R/W: Analogue output data */
-#define ICP_MULTI_DI		8	/* R/W: Digital inouts */
+#define ICP_MULTI_DI		8	/* R/W: Digital inputs */
 #define ICP_MULTI_DO		0x0A	/* R/W: Digital outputs */
 #define ICP_MULTI_INT_EN	0x0C	/* R/W: Interrupt enable register */
 #define ICP_MULTI_INT_STAT	0x0E	/* R/W: Interrupt status register */
@@ -319,7 +319,7 @@ static int icp_multi_insn_bits_do(struct comedi_device *dev,
 	if (comedi_dio_update_state(s, data))
 		writew(s->state, dev->mmio + ICP_MULTI_DO);
 
-	data[1] = readw(dev->mmio + ICP_MULTI_DI);
+	data[1] = s->state;
 
 	return insn->n;
 }