drm/rockchip: vop2: Add error check to devm_regmap_init_mmio

devm_regmap_init_mmio() may return an invalid pointer in case of an error.
This patch adds the corresponding IS_ERR check to vop2->map.
Signed-off-by: Alfredo Cruz <alfredo.carlon@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230322224411.15612-1-alfredo.carlon@gmail.com

drivers/gpu/drm/rockchip/rockchip_drm_vop2.c

@@ -2679,6 +2679,8 @@ static int vop2_bind(struct device *dev, struct device *master, void *data)
 	vop2->len = resource_size(res);
 
 	vop2->map = devm_regmap_init_mmio(dev, vop2->regs, &vop2_regmap_config);
+	if (IS_ERR(vop2->map))
+		return PTR_ERR(vop2->map);
 
 	ret = vop2_win_init(vop2);
 	if (ret)