[media] media-entity.h: convert media_entity_cleanup to inline

This function was used in the past to free the links
that were allocated by the media controller core.

However, this is not needed anymore. We should likely
get rid of the funcion on some function, but, for now,
let's just convert into an inlined function and let the
compiler to get rid of it.
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/media-entity.c

@@ -246,12 +246,6 @@ media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 }
 EXPORT_SYMBOL_GPL(media_entity_pads_init);
 
-void
-media_entity_cleanup(struct media_entity *entity)
-{
-}
-EXPORT_SYMBOL_GPL(media_entity_cleanup);
-
 /* -----------------------------------------------------------------------------
  * Graph traversal
  */

include/media/media-entity.h

@@ -345,7 +345,8 @@ void media_gobj_remove(struct media_gobj *gobj);
 
 int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 		      struct media_pad *pads);
-void media_entity_cleanup(struct media_entity *entity);
+
+static inline void media_entity_cleanup(struct media_entity *entity) {};
 
 __must_check int media_create_pad_link(struct media_entity *source,
 			u16 source_pad, struct media_entity *sink,