media: mc-device.c: use DEVICE_ATTR_RO() helper macro

Use DEVICE_ATTR_RO() helper macro instead of DEVICE_ATTR(), which is
simpler and more readable.

Due to the name of the read function of the sysfs attribute is normalized,
there is a natural association.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/mc/mc-device.c

@@ -556,7 +556,7 @@ static const struct media_file_operations media_device_fops = {
  * sysfs
  */
 
-static ssize_t show_model(struct device *cd,
+static ssize_t model_show(struct device *cd,
 			  struct device_attribute *attr, char *buf)
 {
 	struct media_devnode *devnode = to_media_devnode(cd);
@@ -565,7 +565,7 @@ static ssize_t show_model(struct device *cd,
 	return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 }
 
-static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
+static DEVICE_ATTR_RO(model);
 
 /* -----------------------------------------------------------------------------
  * Registration/unregistration