mac80211: call rate_control_send_low() internally

There's no rate control algorithm that *doesn't* want to call
it internally, and calling it internally will let us modify
its behaviour in the future.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlegacy/3945-rs.c

@@ -646,9 +646,6 @@ il3945_rs_get_rate(void *il_r, struct ieee80211_sta *sta, void *il_sta,
 		il_sta = NULL;
 	}
 
-	if (rate_control_send_low(sta, il_sta, txrc))
-		return;
-
 	rate_mask = sta->supp_rates[sband->band];
 
 	/* get user max rate if set */