libnvdimm/of_pmem: Use devm_kstrdup instead of kstrdup and check its return value

Use devm_kstrdup() instead of kstrdup() and check its return value to
avoid memory leak.

Fixes: 49bddc73 ("libnvdimm/of_pmem: Provide a unique name for bus provider")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

drivers/nvdimm/of_pmem.c

@@ -30,7 +30,13 @@ static int of_pmem_region_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
-	priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
+	priv->bus_desc.provider_name = devm_kstrdup(&pdev->dev, pdev->name,
+							GFP_KERNEL);
+	if (!priv->bus_desc.provider_name) {
+		kfree(priv);
+		return -ENOMEM;
+	}
+
 	priv->bus_desc.module = THIS_MODULE;
 	priv->bus_desc.of_node = np;