staging: comedi: quatech_daqp_cs: cleanup daqp_cs_attach()

Absorb the code from daqp_cs_config() into this function and
properly return the error if the configuration fails.

Remove the dev_dbg() function trace messages.

Fix the kzalloc(). The preferred form for passing a size of a struct
is:

	p = kzalloc(sizeof(*p), ...);

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>