wifi: mac80211: correct EHT EIRP TPE parsing

For the EHT EIRP transmit power envelope, the 320 MHz is in
the last octet, but if we've copied 4 octets (count == 3),
the next one is at index 4 not 5 (count + 2). Fix this, and
just hardcode the offset since count is always 3 here.

Fixes: 39dc8b8e ("wifi: mac80211: pass parsed TPE data to drivers")
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240612100533.f96c1e0fb758.I2f301c4341abb44dafd29128e7e32c66dc0e296d@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/parse.c

@@ -235,7 +235,7 @@ static void ieee80211_parse_tpe(struct ieee80211_parsed_tpe *tpe,
 		*cnt_out = count + 1;
 		/* separately take 320 MHz if present */
 		if (count == 3 && len > sizeof(*env) + count + 1) {
-			out[4] = env->variable[count + 2];
+			out[4] = env->variable[4];
 			*cnt_out = 5;
 		}
 		break;