netlink: remove duplicated nla_need_padding_for_64bit() check

The need for padding 64bit is implicitly checked by nla_align_64bit(), so
remove this explicit one.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lib/nlattr.c

@@ -834,8 +834,7 @@ EXPORT_SYMBOL(__nla_reserve);
 struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
 				   int attrlen, int padattr)
 {
-	if (nla_need_padding_for_64bit(skb))
-		nla_align_64bit(skb, padattr);
+	nla_align_64bit(skb, padattr);
 
 	return __nla_reserve(skb, attrtype, attrlen);
 }