iwlegacy: remove usage of txrc->max_rate_idx

Just calculate it like mac80211 does today, so we can get rid
of the calculation in mac80211 for everyone else.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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

@@ -656,7 +656,7 @@ il3945_rs_get_rate(void *il_r, struct ieee80211_sta *sta, void *il_sta,
 	rate_mask = sta->supp_rates[sband->band];
 
 	/* get user max rate if set */
-	max_rate_idx = txrc->max_rate_idx;
+	max_rate_idx = fls(txrc->rate_idx_mask) - 1;
 	if (sband->band == NL80211_BAND_5GHZ && max_rate_idx != -1)
 		max_rate_idx += IL_FIRST_OFDM_RATE;
 	if (max_rate_idx < 0 || max_rate_idx >= RATE_COUNT)

drivers/net/wireless/intel/iwlegacy/4965-rs.c

@@ -2211,7 +2211,7 @@ il4965_rs_get_rate(void *il_r, struct ieee80211_sta *sta, void *il_sta,
 
 	/* Get max rate if user set max rate */
 	if (lq_sta) {
-		lq_sta->max_rate_idx = txrc->max_rate_idx;
+		lq_sta->max_rate_idx = fls(txrc->rate_idx_mask) - 1;
 		if (sband->band == NL80211_BAND_5GHZ &&
 		    lq_sta->max_rate_idx != -1)
 			lq_sta->max_rate_idx += IL_FIRST_OFDM_RATE;