[PATCH] sky2: handle out of memory on admin changes

Don't die if we run out of memory on mtu or ring parameter change.
For other admin operations, don't rebuild Rx ring, just restart the PHY.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>