Staging: rtl8187se: rename struct ieee80211_hdr to struct ieee80211_hdr_4addr

ieee80211_hdr name is too generic so use ieee80211_hdr_4addr one instead
(which matches the naming used by rtl8192su driver).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>