RDMA/irdma: Return void from irdma_init_iw_device()

The return value from irdma_init_iw_device() is always 0 - change it to be
void.

Link: https://lore.kernel.org/r/20230515191142.413633-2-kheib@redhat.com


Signed-off-by: Kamal Heib <kheib@redhat.com>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>