i2c: digicolor: use clk_disable_unprepare instead of clk_unprepare

since clk_prepare_enable() is used to get i2c->clk, we should
use clk_disable_unprepare() to release it for the error path.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-digicolor.c

@@ -347,7 +347,7 @@ static int dc_i2c_probe(struct platform_device *pdev)
 
 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret < 0) {
-		clk_unprepare(i2c->clk);
+		clk_disable_unprepare(i2c->clk);
 		return ret;
 	}