P2P: Add explicit check for ssid->p2p_client_list != NULL

This would not really be needed since these functions check the pointer
above. However, this seems to be too difficult for some static analyzer,
so add the extra check to avoid false reports.

Signed-off-by: Jouni Malinen <j@w1.fi>

wpa_supplicant/p2p_supplicant.c

@@ -786,7 +786,7 @@ static void wpas_p2p_add_persistent_group_client(struct wpa_supplicant *wpa_s,
 		os_memcpy(n + s->num_p2p_clients * ETH_ALEN, addr, ETH_ALEN);
 		s->p2p_client_list = n;
 		s->num_p2p_clients++;
-	} else if (!found) {
+	} else if (!found && s->p2p_client_list) {
 		/* Not enough room for an additional entry - drop the oldest
 		 * entry */
 		os_memmove(s->p2p_client_list,
@@ -3188,7 +3188,7 @@ static void wpas_remove_persistent_peer(struct wpa_supplicant *wpa_s,
 			      ETH_ALEN) == 0)
 			break;
 	}
-	if (i >= ssid->num_p2p_clients) {
+	if (i >= ssid->num_p2p_clients || !ssid->p2p_client_list) {
 		if (ssid->mode != WPAS_MODE_P2P_GO &&
 		    os_memcmp(ssid->bssid, peer, ETH_ALEN) == 0) {
 			wpa_printf(MSG_DEBUG, "P2P: Remove persistent group %d "