mac80211: move skb info band assignment out

Instead of passing the band as a parameter to ieee80211_xmit()
and ieee80211_tx(), move it outside of the two functions while
making sure info->band is set up before calling them.

This removes the parameter and simplifies the follow commit.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index adc2537..9737251 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1249,7 +1249,8 @@
 		return;
 	}
 
-	ieee80211_xmit(sdata, skb, chanctx_conf->def.chan->band);
+	info->band = chanctx_conf->def.chan->band;
+	ieee80211_xmit(sdata, skb);
 	rcu_read_unlock();
 }