drm/mediatek: Return error if MDP RDMA failed to enable the clock

Return the result of clk_prepare_enable() instead of
always returns 0.

Fixes: f8946e2 ("drm/mediatek: Add display MDP RDMA support for MT8195")

Reviewed-by: CK Hu <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Signed-off-by: Hsiao Chien Sung <[email protected]>
Link: https://patchwork.kernel.org/project/dri-devel/patch/[email protected]/
Signed-off-by: Chun-Kuang Hu <[email protected]>

Author: Hsiao Chien Sung

drivers/gpu/drm/mediatek/mtk_mdp_rdma.c

@@ -262,8 +262,7 @@ int mtk_mdp_rdma_clk_enable(struct device *dev)
 {
 	struct mtk_mdp_rdma *rdma = dev_get_drvdata(dev);
 
-	clk_prepare_enable(rdma->clk);
-	return 0;
+	return clk_prepare_enable(rdma->clk);
 }
 
 void mtk_mdp_rdma_clk_disable(struct device *dev)