ap: Accept P2P wildcard SSIDs in probe requests

Add the special case "DIRECT-" SSID, called the P2P Wildcard SSID, in
ap_probe_req_cb so as not to reject those Probe Requests on the basis of
ssid mismatch.  I'd have preferred to keep all the P2P-specific bits in
p2p.c but in this case there's little point in adding a generic
config setting for SSID-matching quirks.

src/ap.c

@@ -1682,6 +1682,9 @@ static void ap_probe_req_cb(const struct mmpdu_header *hdr, const void *body,
 	else if (ssid && ssid_len == strlen(ap->config->ssid) && /* One SSID */
 			!memcmp(ssid, ap->config->ssid, ssid_len))
 		match = true;
+	else if (ssid && ssid_len == 7 && !memcmp(ssid, "DIRECT-", 7) &&
+			!memcmp(ssid, ap->config->ssid, 7)) /* P2P wildcard */
+		match = true;
 	else if (ssid_list) { /* SSID List */
 		ie_tlv_iter_init(&iter, ssid_list, ssid_list_len);