[media] media: create a macro to get entity ID

Instead of accessing directly entity.id, let's create a macro,
as this field will be moved into a common struct later on.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index c55ab50..e429605 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -77,8 +77,8 @@
 	spin_lock(&mdev->lock);
 
 	media_device_for_each_entity(entity, mdev) {
-		if ((entity->id == id && !next) ||
-		    (entity->id > id && next)) {
+		if (((media_entity_id(entity) == id) && !next) ||
+		    ((media_entity_id(entity) > id) && next)) {
 			spin_unlock(&mdev->lock);
 			return entity;
 		}
@@ -104,7 +104,7 @@
 	if (ent == NULL)
 		return -EINVAL;
 
-	u_ent.id = ent->id;
+	u_ent.id = media_entity_id(ent);
 	if (ent->name)
 		strlcpy(u_ent.name, ent->name, sizeof(u_ent.name));
 	u_ent.type = ent->type;
@@ -122,7 +122,7 @@
 static void media_device_kpad_to_upad(const struct media_pad *kpad,
 				      struct media_pad_desc *upad)
 {
-	upad->entity = kpad->entity->id;
+	upad->entity = media_entity_id(kpad->entity);
 	upad->index = kpad->index;
 	upad->flags = kpad->flags;
 }