iwlwifi: dvm: 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/iwlwifi/dvm/rs.c

@@ -2720,7 +2720,7 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta, void *priv_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 += IWL_FIRST_OFDM_RATE;