mac80211: minstrel_ht: replace some occurences of MCS_GROUP_RATES

Consecutive MCSes in [8*(NSS-1)->8*NSS[ have the same number NSS of
streams (except for MCS32 which is mishandled ATM).
ATM minstrel_ht uses MCS_GROUP_RATES in place of this 8 modulus.
This change replaces such occurences and by doing so allows for different
values of MCS_GROUP_RATES (e.g to cope with VHT MCS8,9).

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 5d60779..0a4a7c7 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -135,7 +135,7 @@
 static int
 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
 {
-	return GROUP_IDX((rate->idx / MCS_GROUP_RATES) + 1,
+	return GROUP_IDX((rate->idx / 8) + 1,
 			 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
 			 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
 }
@@ -148,7 +148,7 @@
 
 	if (rate->flags & IEEE80211_TX_RC_MCS) {
 		group = minstrel_ht_get_group_idx(rate);
-		idx = rate->idx % MCS_GROUP_RATES;
+		idx = rate->idx % 8;
 	} else {
 		group = MINSTREL_CCK_GROUP;
 
@@ -636,8 +636,7 @@
 		idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
 		flags = 0;
 	} else {
-		idx = index % MCS_GROUP_RATES +
-		      (group->streams - 1) * MCS_GROUP_RATES;
+		idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
 		flags = IEEE80211_TX_RC_MCS | group->flags;
 	}
 
@@ -817,7 +816,7 @@
 	}
 
 	rate->idx = sample_idx % MCS_GROUP_RATES +
-		    (sample_group->streams - 1) * MCS_GROUP_RATES;
+		    (sample_group->streams - 1) * 8;
 	rate->flags = IEEE80211_TX_RC_MCS | sample_group->flags;
 }