RDMA/hns: Use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.  This is
detected by coccinelle.

Link: https://lore.kernel.org/r/20190906141727.26552-1-yuehaibing@huawei.comSigned-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hns/hns_roce_hw_v1.c

@@ -4517,7 +4517,6 @@ static int hns_roce_get_cfg(struct hns_roce_dev *hr_dev)
 	struct platform_device *pdev = NULL;
 	struct net_device *netdev = NULL;
 	struct device_node *net_node;
-	struct resource *res;
 	int port_cnt = 0;
 	u8 phy_port;
 	int ret;
@@ -4556,8 +4555,7 @@ static int hns_roce_get_cfg(struct hns_roce_dev *hr_dev)
 	}
 
 	/* get the mapped register base address */
-	res = platform_get_resource(hr_dev->pdev, IORESOURCE_MEM, 0);
-	hr_dev->reg_base = devm_ioremap_resource(dev, res);
+	hr_dev->reg_base = devm_platform_ioremap_resource(hr_dev->pdev, 0);
 	if (IS_ERR(hr_dev->reg_base))
 		return PTR_ERR(hr_dev->reg_base);