drm: Drop plane argument from __drm_atomic_helper_plane_destroy_state

It's unused, and really this helper should only look at the state
structure and nothing else.

v2: Fix commit message (Laurent).

v3: Rebase onto mtk driver merge.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Mark Yao <mark.yao@rock-chips.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462804451-15318-2-git-send-email-daniel.vetter@ffwll.ch
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 39902bb..39940f5 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -434,7 +434,7 @@
 	struct tegra_plane_state *state;
 
 	if (plane->state)
-		__drm_atomic_helper_plane_destroy_state(plane, plane->state);
+		__drm_atomic_helper_plane_destroy_state(plane->state);
 
 	kfree(plane->state);
 	plane->state = NULL;
@@ -466,7 +466,7 @@
 static void tegra_plane_atomic_destroy_state(struct drm_plane *plane,
 					     struct drm_plane_state *state)
 {
-	__drm_atomic_helper_plane_destroy_state(plane, state);
+	__drm_atomic_helper_plane_destroy_state(state);
 	kfree(state);
 }