staging: comedi: ni_mio_cs: cleanup mio_cs_attach()

Remove the DPRINTK() function trace message as well as the #if 0'ed
out debug code that dumps the board "fingerprint".

Remove the need for the local variable that holds the link->irq
passed to request_irq(). Also, return the error code from that
function instead of assuming -EINVAL. Use the dev->board_name for
the resource string passed to request_irq() instead of the open
coded string "ni_mio_cs".

For aesthetic reasons, add some whitespace to the initializatio
of the devpriv values.

Just return the result of ni_E_init() instead of checking it for
an error, returning the error, or returning "0".

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>