drm: cleanup use of Linux list handling macros

This makes the drms use of the list handling macros a lot cleaner
and more along the lines of how they should be used and uses them
in some more places.

Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/i810_dma.c b/drivers/char/drm/i810_dma.c
index 603d17f..53b8a79 100644
--- a/drivers/char/drm/i810_dma.c
+++ b/drivers/char/drm/i810_dma.c
@@ -327,12 +327,10 @@
 			       drm_i810_private_t * dev_priv,
 			       drm_i810_init_t * init)
 {
-	struct list_head *list;
-
+	drm_map_list_t *r_list;
 	memset(dev_priv, 0, sizeof(drm_i810_private_t));
 
-	list_for_each(list, &dev->maplist->head) {
-		drm_map_list_t *r_list = list_entry(list, drm_map_list_t, head);
+	list_for_each_entry(r_list, &dev->maplist, head) {
 		if (r_list->map &&
 		    r_list->map->type == _DRM_SHM &&
 		    r_list->map->flags & _DRM_CONTAINS_LOCK) {