staging: comedi: drivers: return '0' for successful attach

The comedi core expects the driver attach functions to return a
negative errno for failure. Any other value indicates success.

For consistency in the drivers, make sure they all return '0' to
indicate success.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --cc drivers/staging/comedi/drivers/aio_iiro_16.c
Simple merge

diff --cc drivers/staging/comedi/drivers/fl512.c
Simple merge

diff --cc drivers/staging/comedi/drivers/jr3_pci.c
Simple merge

diff --cc drivers/staging/comedi/drivers/mpc624.c
Simple merge

diff --cc drivers/staging/comedi/drivers/ni_pcimio.c
Simple merge

diff --cc drivers/staging/comedi/drivers/s526.c
Simple merge