staging: comedi: quatech_daqp_cs: cleanup subdevice init

Remove the dev_info() board attach noise.

For aesthetic reasons, add some whitespace to the subdevice init.

Remove the init of the s->len_chanlist for the subdevices that do
not support commands. It's not used by them and the comedi core
will handle initializing it properly in the postconfig.

Change the return after a successful attach to "0". The comedi
core expects a < 0 value to indicate an error and "0" is the
typical value returned to indicate success.

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>