mac80211: minstrel_ht: fix per-group max throughput rate initialization

The group number needs to be multiplied by the number of rates per group
to get the full rate index

Fixes: 5935839a ("mac80211: improve minstrel_ht rate sorting by throughput & probability")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20190820095449.45255-1-nbd@nbd.nameSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rc80211_minstrel_ht.c

@@ -575,7 +575,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 
 		/* (re)Initialize group rate indexes */
 		for(j = 0; j < MAX_THR_RATES; j++)
-			tmp_group_tp_rate[j] = group;
+			tmp_group_tp_rate[j] = MCS_GROUP_RATES * group;
 
 		for (i = 0; i < MCS_GROUP_RATES; i++) {
 			if (!(mi->supported[group] & BIT(i)))