firmware: vpd: use kdtrndup when copying section key

Instead of open-coding kstrndup with kzalloc + memcpy, let's use
the helper.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/firmware/google/vpd.c

@@ -118,14 +118,13 @@ static int vpd_section_attrib_add(const u8 *key, s32 key_len,
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;
-	info->key = kzalloc(key_len + 1, GFP_KERNEL);
+
+	info->key = kstrndup(key, key_len, GFP_KERNEL);
 	if (!info->key) {
 		ret = -ENOMEM;
 		goto free_info;
 	}
 
-	memcpy(info->key, key, key_len);
-
 	sysfs_bin_attr_init(&info->bin_attr);
 	info->bin_attr.attr.name = info->key;
 	info->bin_attr.attr.mode = 0444;