IB/hns: fix returnvar.cocci warnings

drivers/infiniband/hw/hns/hns_roce_hw_v1.c:2026:5-8: Unneeded variable: "ret". Return "0" on line 2046

 Remove unneeded variable used to store return value.

Generated by: scripts/coccinelle/misc/returnvar.cocci

Fixes: 7d1b6a678e0b ("IB/hns: Support compile test for hns RoCE driver")
CC: Matan Barak <matanb@mellanox.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>