staging: comedi: usbduxsigma: cleanup the unlink urb functions
staging: comedi: usbduxsigma: cleanup the unlink urb functions

These functions always return success. Change them to just return void.

The 'usbduxsub_tmp', which is actually the comedi_device private data, is
already validated by the callers. Remove the unnecessary validation and
rename the 'usbduxsub_tmp' parameter to 'devpriv' which is more common in
comedi drivers.

Remove the unnecessary comments.

Signed-off-by: H Hartley Sweeten <382ff55d8e07d1082d179e669636cd1552da4f36@visionengravers.com>
Cc: Ian Abbott <9e6ba6483b6a3e14d61f7c987e72ecb5b46122d6@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs