staging: comedi: ni_mio_common: fix subdevice flags for PFI subdevice

The PFI subdevice flags indicate that the subdevice is readable and
writeable, but that is only true for the supported "M-series" boards,
not the older "E-series" boards.  Only set the SDF_READABLE and
SDF_WRITABLE subdevice flags for the M-series boards.  These two flags
are mainly for informational purposes.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_mio_common.c

@@ -5446,11 +5446,11 @@ static int ni_E_init(struct comedi_device *dev,
 	/* Digital I/O (PFI) subdevice */
 	s = &dev->subdevices[NI_PFI_DIO_SUBDEV];
 	s->type		= COMEDI_SUBD_DIO;
-	s->subdev_flags	= SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
 	s->maxdata	= 1;
 	if (devpriv->is_m_series) {
 		s->n_chan	= 16;
 		s->insn_bits	= ni_pfi_insn_bits;
+		s->subdev_flags	= SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
 
 		ni_writew(dev, s->state, NI_M_PFI_DO_REG);
 		for (i = 0; i < NUM_PFI_OUTPUT_SELECT_REGS; ++i) {
@@ -5459,6 +5459,7 @@ static int ni_E_init(struct comedi_device *dev,
 		}
 	} else {
 		s->n_chan	= 10;
+		s->subdev_flags	= SDF_INTERNAL;
 	}
 	s->insn_config	= ni_pfi_insn_config;