[PPP]: Don't leak an sk_buff on interface destruction.
Signed-off-by: G. Liakhovetski <gl@dsa-ac.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>