RDMA/hns: Modify function return value type

hns_roce_init_qp_table() will only return 0, because this function does
not need to return a value, so it is modified to void type.

Link: https://lore.kernel.org/r/1624011020-16992-8-git-send-email-liweihang@huawei.com
Signed-off-by: Yangyang Li <liyangyang20@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>