[PATCH] sky2: use netdev_alloc_skb

Use netdev_alloc_skb for buffer allocation to allow for headroom.
This prevents bugs in code paths that assume extra space at the
front and makes sky2 behave like other drivers.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>