[PATCH] hostap: Replace hostap_ieee80211_hdr with ieee80211_hdr

Replace hostap-specific struct hostap_ieee80211_hdr with struct
ieee80211_hdr from net/ieee80211.h.

Signed-off-by: Jouni Malinen <jkmaline@cc.hut.fi>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>