i2c: mt7621: fix missing clk_disable_unprepare() on error in mtk_i2c_probe()

Fix the missing clk_disable_unprepare() before return
from mtk_i2c_probe() in the error handling case.

Fixes: d04913ec5f89 ("i2c: mt7621: Add MediaTek MT7621/7628/7688 I2C driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
diff --git a/drivers/i2c/busses/i2c-mt7621.c b/drivers/i2c/busses/i2c-mt7621.c
index 45fe4a7..901f0fb 100644
--- a/drivers/i2c/busses/i2c-mt7621.c
+++ b/drivers/i2c/busses/i2c-mt7621.c
@@ -304,7 +304,8 @@
 
 	if (i2c->bus_freq == 0) {
 		dev_warn(i2c->dev, "clock-frequency 0 not supported\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_disable_clk;
 	}
 
 	adap = &i2c->adap;
@@ -322,10 +323,15 @@
 
 	ret = i2c_add_adapter(adap);
 	if (ret < 0)
-		return ret;
+		goto err_disable_clk;
 
 	dev_info(&pdev->dev, "clock %u kHz\n", i2c->bus_freq / 1000);
 
+	return 0;
+
+err_disable_clk:
+	clk_disable_unprepare(i2c->clk);
+
 	return ret;
 }