Old AP mode code for power saving was using skb->cb for couple of
flags before the more generic 802.11 TX code started using the same
buffer for struct hostap_skb_tx_data. This resulted in the power save
code corrupting the magic value in beginning of the buffer and TX code
dropping the power saved packets because of this for the case where
STAs send PS-Poll frames with PwrMgmt flag set.

This patch modifies the power save code to use the same struct
hostap_skb_tx_data as rest of the TX path in order to avoid corrupting
the data in skb->cb.

In addition, this patch reorders fields in the structure and makes
them use smaller types in order to make the structure fit in skb->cb
on 64-bit hosts.
Signed-off-by: Jouni Malinen <jkmaline@cc.hut.fi>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>