drm/mediatek: mtk_drm_crtc: Use kmalloc in mtk_drm_crtc_duplicate_state

Optimize mtk_drm_crtc_duplicate_state() by switching from kzalloc() to
kmalloc(): the only variable of this struct that gets checked in other
functions is `pending_config`, but if that's set to false, then all of
the remaining variables will only ever be set, but not read - so, also
set `pending_config` to false.
This saves us some small overhead.

Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20220118133759.112458-2-angelogioacchino.delregno@collabora.com/Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -184,7 +184,7 @@ static struct drm_crtc_state *mtk_drm_crtc_duplicate_state(struct drm_crtc *crtc
 {
 	struct mtk_crtc_state *state;
 
-	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
 	if (!state)
 		return NULL;
 
@@ -192,6 +192,7 @@ static struct drm_crtc_state *mtk_drm_crtc_duplicate_state(struct drm_crtc *crtc
 
 	WARN_ON(state->base.crtc != crtc);
 	state->base.crtc = crtc;
+	state->pending_config = false;
 
 	return &state->base;
 }