cfg80211: fix 6 GHz channel conversion

We shouldn't accept any channels bigger than 233, fix that.
Reported-by: Amar <asinghal@codeaurora.org>
Fixes: d1a1646c ("cfg80211: adapt to new channelization of the 6GHz band")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200917115222.312ba6f1d461.I3a8c8fbcc3cc019814fd9cd0aced7eb591626136@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/util.c

@@ -95,7 +95,7 @@ u32 ieee80211_channel_to_freq_khz(int chan, enum nl80211_band band)
 		/* see 802.11ax D6.1 27.3.23.2 */
 		if (chan == 2)
 			return MHZ_TO_KHZ(5935);
-		if (chan <= 253)
+		if (chan <= 233)
 			return MHZ_TO_KHZ(5950 + chan * 5);
 		break;
 	case NL80211_BAND_60GHZ: