mac80211: clean up IEEE80211_FC use

Really doesn't need to be defined four times.

Also, while at it, remove a useless macro (IEEE80211_ALIGN32_PAD)
and a function prototype for a function we don't actually have
(ieee80211_set_compression.)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --cc net/mac80211/ieee80211_i.h
Simple merge

diff --cc net/mac80211/ieee80211_sta.c
Simple merge

diff --cc net/mac80211/mesh_hwmp.c
Simple merge

diff --cc net/mac80211/mesh_plink.c
Simple merge