RDMA/hns: Do not overwrite the error code during error unwind in hns_roce_init

When init cmq fail in initial flow of RoCE, it should return the errno of
cmq_init function, not of the rest call.

Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>