mac80211: minstrel_ht: make att_hist and succ_hist u32 instead of u64

They are only used for debugging purposes and take a very long time to
overflow. Visibly reduces the size of the per-sta rate control data.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rc80211_minstrel.h

@@ -59,7 +59,7 @@ struct minstrel_rate_stats {
 	u16 success, last_success;
 
 	/* total attempts/success counters */
-	u64 att_hist, succ_hist;
+	u32 att_hist, succ_hist;
 
 	/* statistis of packet delivery probability
 	 *  cur_prob  - current prob within last update intervall