mtd: st_spi_fsm: Handle clk_prepare_enable/clk_disable_unprepare.

- clk_prepare_enable() can fail here and we must check its return value.
 - stfsm_probe() can fail here and we must disable clock.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/devices/st_spi_fsm.c

@@ -2073,15 +2073,17 @@ static int stfsm_probe(struct platform_device *pdev)
 	ret = stfsm_init(fsm);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to initialise FSM Controller\n");
-		return ret;
+		goto err_clk_unprepare;
 	}
 
 	stfsm_fetch_platform_configs(pdev);
 
 	/* Detect SPI FLASH device */
 	info = stfsm_jedec_probe(fsm);
-	if (!info)
-		return -ENODEV;
+	if (!info) {
+		ret = -ENODEV;
+		goto err_clk_unprepare;
+	}
 	fsm->info = info;
 
 	/* Use device size to determine address width */
@@ -2095,11 +2097,11 @@ static int stfsm_probe(struct platform_device *pdev)
 	if (info->config) {
 		ret = info->config(fsm);
 		if (ret)
-			return ret;
+			goto err_clk_unprepare;
 	} else {
 		ret = stfsm_prepare_rwe_seqs_default(fsm);
 		if (ret)
-			return ret;
+			goto err_clk_unprepare;
 	}
 
 	fsm->mtd.name		= info->name;
@@ -2124,6 +2126,10 @@ static int stfsm_probe(struct platform_device *pdev)
 		fsm->mtd.erasesize, (fsm->mtd.erasesize >> 10));
 
 	return mtd_device_register(&fsm->mtd, NULL, 0);
+
+err_clk_unprepare:
+	clk_disable_unprepare(fsm->clk);
+	return ret;
 }
 
 static int stfsm_remove(struct platform_device *pdev)
@@ -2147,9 +2153,7 @@ static int stfsmfsm_resume(struct device *dev)
 {
 	struct stfsm *fsm = dev_get_drvdata(dev);
 
-	clk_prepare_enable(fsm->clk);
-
-	return 0;
+	return clk_prepare_enable(fsm->clk);
 }
 #endif