ppp: avoid false drop_monitor false positives

Call consume_skb() in place of kfree_skb() were appropriate.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ppp/ppp_synctty.c b/drivers/net/ppp/ppp_synctty.c
index 55e466c..1a12033 100644
--- a/drivers/net/ppp/ppp_synctty.c
+++ b/drivers/net/ppp/ppp_synctty.c
@@ -588,7 +588,7 @@
 			skb_reserve(npkt,2);
 			skb_copy_from_linear_data(skb,
 				      skb_put(npkt, skb->len), skb->len);
-			kfree_skb(skb);
+			consume_skb(skb);
 			skb = npkt;
 		}
 		skb_push(skb,2);
@@ -656,7 +656,7 @@
 			if (sent < ap->tpkt->len) {
 				tty_stuffed = 1;
 			} else {
-				kfree_skb(ap->tpkt);
+				consume_skb(ap->tpkt);
 				ap->tpkt = NULL;
 				clear_bit(XMIT_FULL, &ap->xmit_flags);
 				done = 1;