pppoe: warning fix

Fix warning:
drivers/net/pppoe.c: In function 'pppoe_recvmsg':
drivers/net/pppoe.c:945: warning: comparison of distinct pointer types lacks a cast
because skb->len is unsigned int and total_len is size_t

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/pppoe.c b/drivers/net/pppoe.c
index bafb69b..fc6f4b8 100644
--- a/drivers/net/pppoe.c
+++ b/drivers/net/pppoe.c
@@ -942,7 +942,7 @@
 	m->msg_namelen = 0;
 
 	if (skb) {
-		total_len = min(total_len, skb->len);
+		total_len = min_t(size_t, total_len, skb->len);
 		error = skb_copy_datagram_iovec(skb, 0, m->msg_iov, total_len);
 		if (error == 0)
 			error = total_len;