Merge 4.18-rc5 into char-misc-next

We want the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/core.c

@@ -934,6 +934,10 @@ struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id)
 			return cell;
 	}
 
+	/* NULL cell_id only allowed for device tree; invalid otherwise */
+	if (!cell_id)
+		return ERR_PTR(-EINVAL);
+
 	return nvmem_cell_get_from_list(cell_id);
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_get);