qeth: Fix command sizes

This patch adjusts two instances where we were using the (too big)
struct qeth_ipacmd_setadpparms size instead of the commands' actual
size. This didn't do any harm, but wasted a few bytes.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>