mac80211: remove set but unused variables

Compiling with W=1 found a few variables that are set
but not used (-Wunused-but-set-variable), remove them.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/ibss.c

@@ -220,7 +220,6 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 	struct ieee80211_local *local = sdata->local;
-	struct ieee80211_supported_band *sband;
 	struct ieee80211_mgmt *mgmt;
 	struct cfg80211_bss *bss;
 	u32 bss_change;
@@ -307,8 +306,6 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
 
-	sband = local->hw.wiphy->bands[chan->band];
-
 	presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
 					   capability, tsf, &chandef,
 					   &have_higher_than_11mbit, NULL);

net/mac80211/status.c

@@ -479,7 +479,7 @@ static void ieee80211_tx_latency_end_msrmnt(struct ieee80211_local *local,
 	u32 msrmnt;
 	u16 tid;
 	u8 *qc;
-	int i, bin_range_count, bin_count;
+	int i, bin_range_count;
 	u32 *bin_ranges;
 	__le16 fc;
 	struct ieee80211_tx_latency_stat *tx_lat;
@@ -522,7 +522,6 @@ static void ieee80211_tx_latency_end_msrmnt(struct ieee80211_local *local,
 	/* count how many Tx frames transmitted with the appropriate latency */
 	bin_range_count = tx_latency->n_ranges;
 	bin_ranges = tx_latency->ranges;
-	bin_count = tx_lat->bin_count;
 
 	for (i = 0; i < bin_range_count; i++) {
 		if (msrmnt <= bin_ranges[i]) {

net/mac80211/util.c

@@ -1374,7 +1374,6 @@ u32 ieee80211_sta_get_rates(struct ieee80211_sub_if_data *sdata,
 			    enum ieee80211_band band, u32 *basic_rates)
 {
 	struct ieee80211_supported_band *sband;
-	struct ieee80211_rate *bitrates;
 	size_t num_rates;
 	u32 supp_rates, rate_flags;
 	int i, j, shift;
@@ -1386,7 +1385,6 @@ u32 ieee80211_sta_get_rates(struct ieee80211_sub_if_data *sdata,
 	if (WARN_ON(!sband))
 		return 1;
 
-	bitrates = sband->bitrates;
 	num_rates = sband->n_bitrates;
 	supp_rates = 0;
 	for (i = 0; i < elems->supp_rates_len +