[PATCH -next] iommu/amd: use DEVICE_ATTR_RO macro

[YueHaibing]

Use DEVICE_ATTR_RO() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
---
 drivers/iommu/amd/init.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index d006724f4dc2..4ffb694bd297 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1731,23 +1731,21 @@ static void init_iommu_perf_ctr(struct amd_iommu *iommu)
 	return;
 }
 
-static ssize_t amd_iommu_show_cap(struct device *dev,
-				  struct device_attribute *attr,
-				  char *buf)
+static ssize_t cap_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
 {
 	struct amd_iommu *iommu = dev_to_amd_iommu(dev);
 	return sprintf(buf, "%x\n", iommu->cap);
 }
-static DEVICE_ATTR(cap, S_IRUGO, amd_iommu_show_cap, NULL);
+static DEVICE_ATTR_RO(cap);
 
-static ssize_t amd_iommu_show_features(struct device *dev,
-				       struct device_attribute *attr,
-				       char *buf)
+static ssize_t features_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
 {
 	struct amd_iommu *iommu = dev_to_amd_iommu(dev);
 	return sprintf(buf, "%llx\n", iommu->features);
 }
-static DEVICE_ATTR(features, S_IRUGO, amd_iommu_show_features, NULL);
+static DEVICE_ATTR_RO(features);
 
 static struct attribute *amd_iommu_attrs[] = {
 	&dev_attr_cap.attr,
-- 
2.17.1