cfg80211: ignore supported rates for nonexistant bands on scan

Fixes wpa_supplicant p2p_find on 5GHz-only devices
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -5349,6 +5349,10 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
 				err = -EINVAL;
 				goto out_free;
 			}
+
+			if (!wiphy->bands[band])
+				continue;
+
 			err = ieee80211_get_ratemask(wiphy->bands[band],
 						     nla_data(attr),
 						     nla_len(attr),