linux-phytec-ti

pptp: fix skb leak in pptp_xmit()

In case we cant transmit skb, we must free it

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>