mtd: plat-ram: correctly free memory on error path in platram_probe()

If an error happens in mtd_device_parse_register or mtd_device_register,
memory allocated for struct platram_info is leaked.

Make platram_probe() call platram_remove() on all error paths
after struct platram_info allocation to correctly free resources.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Baskov Evgeiny <baskov@ispras.ru>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201113160537.899-1-baskov@ispras.ru

drivers/mtd/maps/plat-ram.c

@@ -177,8 +177,12 @@ static int platram_probe(struct platform_device *pdev)
 	err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,
 					pdata->partitions,
 					pdata->nr_partitions);
-	if (!err)
-		dev_info(&pdev->dev, "registered mtd device\n");
+	if (err) {
+		dev_err(&pdev->dev, "failed to register mtd device\n");
+		goto exit_free;
+	}
+
+	dev_info(&pdev->dev, "registered mtd device\n");
 
 	if (pdata->nr_partitions) {
 		/* add the whole device. */
@@ -186,10 +190,11 @@ static int platram_probe(struct platform_device *pdev)
 		if (err) {
 			dev_err(&pdev->dev,
 				"failed to register the entire device\n");
+			goto exit_free;
 		}
 	}
 
-	return err;
+	return 0;
 
  exit_free:
 	platram_remove(pdev);