ASoC: mediatek: mtk-btcvsd: Fix an error handling path in 'mtk_btcvsd_snd_probe()'

If an error occurs after a successful 'of_iomap()' call, it must be undone
by a corresponding 'iounmap()' call, as already done in the remove
function.

While at it, remove the useless initialization of 'ret' at the beginning of
the function.

Fixes: 4bd8597d ("ASoC: mediatek: add btcvsd driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/0c2ba562c3364e61bfbd5b3013a99dfa0d9045d7.1622989685.git.christophe.jaillet@wanadoo.frSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/common/mtk-btcvsd.c

@@ -1281,7 +1281,7 @@ static const struct snd_soc_component_driver mtk_btcvsd_snd_platform = {
 
 static int mtk_btcvsd_snd_probe(struct platform_device *pdev)
 {
-	int ret = 0;
+	int ret;
 	int irq_id;
 	u32 offset[5] = {0, 0, 0, 0, 0};
 	struct mtk_btcvsd_snd *btcvsd;
@@ -1337,7 +1337,8 @@ static int mtk_btcvsd_snd_probe(struct platform_device *pdev)
 	btcvsd->bt_sram_bank2_base = of_iomap(dev->of_node, 1);
 	if (!btcvsd->bt_sram_bank2_base) {
 		dev_err(dev, "iomap bt_sram_bank2_base fail\n");
-		return -EIO;
+		ret = -EIO;
+		goto unmap_pkv_err;
 	}
 
 	btcvsd->infra = syscon_regmap_lookup_by_phandle(dev->of_node,
@@ -1345,7 +1346,8 @@ static int mtk_btcvsd_snd_probe(struct platform_device *pdev)
 	if (IS_ERR(btcvsd->infra)) {
 		dev_err(dev, "cannot find infra controller: %ld\n",
 			PTR_ERR(btcvsd->infra));
-		return PTR_ERR(btcvsd->infra);
+		ret = PTR_ERR(btcvsd->infra);
+		goto unmap_bank2_err;
 	}
 
 	/* get offset */
@@ -1354,7 +1356,7 @@ static int mtk_btcvsd_snd_probe(struct platform_device *pdev)
 					 ARRAY_SIZE(offset));
 	if (ret) {
 		dev_warn(dev, "%s(), get offset fail, ret %d\n", __func__, ret);
-		return ret;
+		goto unmap_bank2_err;
 	}
 	btcvsd->infra_misc_offset = offset[0];
 	btcvsd->conn_bt_cvsd_mask = offset[1];
@@ -1373,8 +1375,18 @@ static int mtk_btcvsd_snd_probe(struct platform_device *pdev)
 	mtk_btcvsd_snd_set_state(btcvsd, btcvsd->tx, BT_SCO_STATE_IDLE);
 	mtk_btcvsd_snd_set_state(btcvsd, btcvsd->rx, BT_SCO_STATE_IDLE);
 
-	return devm_snd_soc_register_component(dev, &mtk_btcvsd_snd_platform,
+	ret = devm_snd_soc_register_component(dev, &mtk_btcvsd_snd_platform,
 					      NULL, 0);
+	if (ret)
+		goto unmap_bank2_err;
+
+	return 0;
+
+unmap_bank2_err:
+	iounmap(btcvsd->bt_sram_bank2_base);
+unmap_pkv_err:
+	iounmap(btcvsd->bt_pkv_base);
+	return ret;
 }
 
 static int mtk_btcvsd_snd_remove(struct platform_device *pdev)