RDMA/hns: Optimize hns_roce_v2_set_mac()

Removes the unnecessary memset opertaion and adjust style of some lines in
hns_roce_v2_set_mac().

Link: https://lore.kernel.org/r/1586938475-37049-3-git-send-email-liweihang@huawei.com
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -2427,12 +2427,9 @@ static int hns_roce_v2_set_mac(struct hns_roce_dev *hr_dev, u8 phy_port,
 	reg_smac_l = *(u32 *)(&addr[0]);
 	reg_smac_h = *(u16 *)(&addr[4]);
 
-	memset(smac_tb, 0, sizeof(*smac_tb));
+	roce_set_field(smac_tb->tb_idx_rsv, CFG_SMAC_TB_IDX_M,
-	roce_set_field(smac_tb->tb_idx_rsv,
-		       CFG_SMAC_TB_IDX_M,
 		       CFG_SMAC_TB_IDX_S, phy_port);
-	roce_set_field(smac_tb->vf_smac_h_rsv,
+	roce_set_field(smac_tb->vf_smac_h_rsv, CFG_SMAC_TB_VF_SMAC_H_M,
-		       CFG_SMAC_TB_VF_SMAC_H_M,
 		       CFG_SMAC_TB_VF_SMAC_H_S, reg_smac_h);
 	smac_tb->vf_smac_l = cpu_to_le32(reg_smac_l);