staging: comedi: contec_pci_dio: cleanup contec_do_insn_bits

Create local variables for the mask and bits values passed in
the data pointer to make this function a bit clearer.

Return the state of the output bits (s->state) in data[1] since
this is what comedilib is expecting.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/contec_pci_dio.c

@@ -44,12 +44,18 @@ static int contec_do_insn_bits(struct comedi_device *dev,
 			       struct comedi_subdevice *s,
 			       struct comedi_insn *insn, unsigned int *data)
 {
-	if (data[0]) {
-		s->state &= ~data[0];
-		s->state |= data[0] & data[1];
+	unsigned int mask = data[0];
+	unsigned int bits = data[1];
+
+	if (mask) {
+		s->state &= ~mask;
+		s->state |= (bits & mask);
 
 		outw(s->state, dev->iobase + PIO1616L_DO_REG);
 	}
+
+	data[1] = s->state;
+
 	return insn->n;
 }