wireless: restrict to 32 legacy rates

Since the standards only define 12 legacy rates, 32 is certainly
a sane upper limit and we don't need to use u64 everywhere. Add
sanity checking that no more than 32 rates are registered and
change the variables to u32 throughout.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2x00.h

@@ -396,7 +396,7 @@ struct rt2x00lib_erp {
 	int ack_timeout;
 	int ack_consume_time;
 
-	u64 basic_rates;
+	u32 basic_rates;
 
 	int slot_time;