hostapd: fix MAC overlap with MBSSID enabled

Reverse byte order in non-OUI part of MAC address to prevent overlap
when MBSSID is enabled. Swaps bytes 3 and 5 and masks lower nibble
of byte 5 before applying index XOR.

Signed-off-by: John Crispin <john@phrozen.org>

feeds/qca-wifi-7/hostapd/files/common.uc

@@ -259,8 +259,13 @@ const phy_proto = {
 			addr[0] ^= idx << 2;
 			break;
 		case "b5":
-			if (mbssid)
+			if (mbssid) {
+				let b5 = addr[5];
+				addr[5] = addr[3];
+				addr[3] = b5;
+				addr[5] &= ~0xf;
 				addr[0] |= 2;
+			}
 			addr[5] ^= idx;
 			break;
 		default: