s390/qeth: clarify remaining dev_kfree_skb_any() users

For none of the users we are under risk of running in HW IRQ context or
or with IRQs disabled. Thus we always end up in consume_skb().

But the two occurences in the RX path should really report the dropped
packet to dropmon, so have them use kfree_skb() instead. That's also
consistent with what napi_free_frags() does internally.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>