[media] vcodec: mediatek: fix odd_ptr_err.cocci warnings

PTR_ERR should access the value just tested by IS_ERR

Generated by: scripts/coccinelle/tests/odd_ptr_err.cocci

CC: Tiffany Lin <[e-mail]>
Signed-off-by: Julia Lawall <[e-mail]>
Signed-off-by: Fengguang Wu <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c

···
 		}
 		dev->reg_base[i] = devm_ioremap_resource(&pdev->dev, res);
 		if (IS_ERR((__force void *)dev->reg_base[i])) {
-			ret = PTR_ERR((__force void *)dev->reg_base);
+			ret = PTR_ERR((__force void *)dev->reg_base[i]);
 			goto err_res;
 		}
 		mtk_v4l2_debug(2, "reg[%d] base=%p", i, dev->reg_base[i]);