packet: Add needed_tailroom to packet_sendmsg_spkt

packet: Add needed_tailroom to packet_sendmsg_spkt

While auditing LL_ALLOCATED_SPACE I noticed that packet_sendmsg_spkt
did not include needed_tailroom when allocating an skb.  This isn't
a fatal error as we should always tolerate inadequate tail room but
it isn't optimal.

This patch fixes that.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet/af_packet.c

@@ -1499,10 +1499,11 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
 
 	if (!skb) {
 		size_t reserved = LL_RESERVED_SPACE(dev);
+		int tlen = dev->needed_tailroom;
 		unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
 
 		rcu_read_unlock();
-		skb = sock_wmalloc(sk, len + reserved, 0, GFP_KERNEL);
+		skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
 		if (skb == NULL)
 			return -ENOBUFS;
 		/* FIXME: Save some space for broken drivers that write a hard