staging: comedi: usbduxsigma: remove private data sanity checks

The comedi functions in this driver can only be called if the
(*auto_attach) successfull kzalloc'ed the private data and set
dev->private. The extra sanity checks are not needed. Remove them.
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/usbduxsigma.c

@@ -759,8 +759,6 @@ static int usbdux_ai_inttrig(struct comedi_device *dev,
 {
 	struct usbduxsigma_private *this_usbduxsub = dev->private;
 	int ret;
-	if (!this_usbduxsub)
-		return -EFAULT;
 
 	down(&this_usbduxsub->sem);
 	if (trignum != 0) {
@@ -800,9 +798,6 @@ static int usbdux_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	uint8_t muxsg1 = 0;
 	uint8_t sysred = 0;
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	/* block other CPUs from starting an ai_cmd */
 	down(&this_usbduxsub->sem);
 	if (this_usbduxsub->ai_cmd_running) {
@@ -918,9 +913,6 @@ static int usbdux_ai_insn_read(struct comedi_device *dev,
 	uint8_t muxsg1 = 0;
 	uint8_t sysred = 0;
 
-	if (!this_usbduxsub)
-		return 0;
-
 	down(&this_usbduxsub->sem);
 	if (this_usbduxsub->ai_cmd_running) {
 		dev_err(&this_usbduxsub->interface->dev,
@@ -983,9 +975,6 @@ static int usbdux_getstatusinfo(struct comedi_device *dev, int chan)
 	uint32_t one;
 	int err;
 
-	if (!this_usbduxsub)
-		return 0;
-
 	if (this_usbduxsub->ai_cmd_running) {
 		dev_err(&this_usbduxsub->interface->dev,
 			"comedi%d: status read not possible. "
@@ -1057,9 +1046,6 @@ static int usbdux_ao_insn_read(struct comedi_device *dev,
 	int i;
 	int chan = CR_CHAN(insn->chanspec);
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	down(&this_usbduxsub->sem);
 	for (i = 0; i < insn->n; i++)
 		data[i] = this_usbduxsub->outBuffer[chan];
@@ -1076,9 +1062,6 @@ static int usbdux_ao_insn_write(struct comedi_device *dev,
 	int i, err;
 	int chan = CR_CHAN(insn->chanspec);
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	down(&this_usbduxsub->sem);
 	if (this_usbduxsub->ao_cmd_running) {
 		dev_err(&this_usbduxsub->interface->dev,
@@ -1116,9 +1099,6 @@ static int usbdux_ao_inttrig(struct comedi_device *dev,
 	struct usbduxsigma_private *this_usbduxsub = dev->private;
 	int ret;
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	down(&this_usbduxsub->sem);
 	if (trignum != 0) {
 		dev_err(&this_usbduxsub->interface->dev,
@@ -1150,13 +1130,9 @@ static int usbdux_ao_cmdtest(struct comedi_device *dev,
 			     struct comedi_subdevice *s,
 			     struct comedi_cmd *cmd)
 {
-	struct usbduxsigma_private *this_usbduxsub = dev->private;
 	int err = 0;
 	unsigned int flags;
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	/* Step 1 : check if triggers are trivially valid */
 
 	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
@@ -1227,9 +1203,6 @@ static int usbdux_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	unsigned int chan, gain;
 	int i, ret;
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	down(&this_usbduxsub->sem);
 	/* set current channel of the running acquisition to zero */
 	s->async->cur_chan = 0;
@@ -1360,9 +1333,6 @@ static int usbdux_dio_insn_bits(struct comedi_device *dev,
 	struct usbduxsigma_private *this_usbduxsub = dev->private;
 	int err;
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	down(&this_usbduxsub->sem);
 
 	/* The insn data is a mask in data[0] and the new data
@@ -1549,9 +1519,6 @@ static int usbdux_pwm_pattern(struct comedi_device *dev,
 	char sgn_mask;
 	char c;
 
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	/* this is the DIO bit which carries the PWM data */
 	pwm_mask = (1 << channel);
 	/* this is the DIO bit which carries the optional direction bit */
@@ -1584,11 +1551,6 @@ static int usbdux_pwm_write(struct comedi_device *dev,
 			    struct comedi_subdevice *s,
 			    struct comedi_insn *insn, unsigned int *data)
 {
-	struct usbduxsigma_private *this_usbduxsub = dev->private;
-
-	if (!this_usbduxsub)
-		return -EFAULT;
-
 	if ((insn->n) != 1) {
 		/*
 		 * doesn't make sense to have more than one value here because
@@ -1667,9 +1629,6 @@ static void tidy_up(struct usbduxsigma_private *usbduxsub_tmp)
 {
 	int i;
 
-	if (!usbduxsub_tmp)
-		return;
-
 	/* shows the usb subsystem that the driver is down */
 	if (usbduxsub_tmp->interface)
 		usb_set_intfdata(usbduxsub_tmp->interface, NULL);