mtd: nand: nandsim: fix error check

debugfs_create_dir() and debugfs_create_file() returns NULL on error or
a pointer on success. They do not return the error value with ERR_PTR.
So we should not check the return with IS_ERR_OR_NULL, instead we
should just check for NULL.
Signed-off-by: NSudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nandsim.c

@@ -525,24 +525,20 @@ static int nandsim_debugfs_create(struct nandsim *dev)
 {
 	struct nandsim_debug_info *dbg = &dev->dbg;
 	struct dentry *dent;
-	int err;
 
 	if (!IS_ENABLED(CONFIG_DEBUG_FS))
 		return 0;
 
 	dent = debugfs_create_dir("nandsim", NULL);
-	if (IS_ERR_OR_NULL(dent)) {
-		int err = dent ? -ENODEV : PTR_ERR(dent);
-
-		NS_ERR("cannot create \"nandsim\" debugfs directory, err %d\n",
-			err);
-		return err;
+	if (!dent) {
+		NS_ERR("cannot create \"nandsim\" debugfs directory\n");
+		return -ENODEV;
 	}
 	dbg->dfs_root = dent;
 
 	dent = debugfs_create_file("wear_report", S_IRUSR,
 				   dbg->dfs_root, dev, &dfs_fops);
-	if (IS_ERR_OR_NULL(dent))
+	if (!dent)
 		goto out_remove;
 	dbg->dfs_wear_report = dent;
 
@@ -550,8 +546,7 @@ static int nandsim_debugfs_create(struct nandsim *dev)
 
 out_remove:
 	debugfs_remove_recursive(dbg->dfs_root);
-	err = dent ? PTR_ERR(dent) : -ENODEV;
-	return err;
+	return -ENODEV;
 }
 
 /**