nvmem: sunplus-ocotp: release otp->clk before return

Smatch reports:
drivers/nvmem/sunplus-ocotp.c:205 sp_ocotp_probe()
warn: 'otp->clk' from clk_prepare() not released on lines: 196.

In the function sp_ocotp_probe(struct platform_device *pdev), otp->clk may
not be released before return.

To fix this issue, using function clk_unprepare() to release otp->clk.

Fixes: 8747ec2e ("nvmem: Add driver for OCOTP in Sunplus SP7021")
Signed-off-by: Yi Yingao <m202271736@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Message-ID: <20230509085237.5917-1-m202271736@hust.edu.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/sunplus-ocotp.c

@@ -192,9 +192,11 @@ static int sp_ocotp_probe(struct platform_device *pdev)
 	sp_ocotp_nvmem_config.dev = dev;
 
 	nvmem = devm_nvmem_register(dev, &sp_ocotp_nvmem_config);
-	if (IS_ERR(nvmem))
-		return dev_err_probe(&pdev->dev, PTR_ERR(nvmem),
+	if (IS_ERR(nvmem)) {
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(nvmem),
 						"register nvmem device fail\n");
+		goto err;
+	}
 
 	platform_set_drvdata(pdev, nvmem);
 
@@ -203,6 +205,9 @@ static int sp_ocotp_probe(struct platform_device *pdev)
 		(int)OTP_WORD_SIZE, (int)QAC628_OTP_SIZE);
 
 	return 0;
+err:
+	clk_unprepare(otp->clk);
+	return ret;
 }
 
 static const struct of_device_id sp_ocotp_dt_ids[] = {