net: ip_push_pending_frames() fix

After commit 2b85a34e


(net: No more expensive sock_hold()/sock_put() on each tx)
we do not take any more references on sk->sk_refcnt on outgoing packets.

I forgot to delete two __sock_put() from ip_push_pending_frames()
and ip6_push_pending_frames().

Reported-by: Emil S Tantilov <emils.tantilov@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Emil S Tantilov <emils.tantilov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>