qeth: convert to SKB paged frag API.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Ursula Braun <ursula.braun@de.ibm.com>
Cc: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Cc: linux390@de.ibm.com
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>