db: remount read-only after the file handles have been closed

The apk cache might be on the readonly media so we need wait with
remounting til after atleast this filehandle is closed.

src/database.c

@@ -1397,12 +1397,6 @@ void apk_db_close(struct apk_database *db)
 	struct hlist_node *dc, *dn;
 	int i;
 
-	if (db->cache_remount_dir) {
-		do_remount(db->cache_remount_dir, "ro");
-		free(db->cache_remount_dir);
-		db->cache_remount_dir = NULL;
-	}
-
 	apk_id_cache_free(&db->id_cache);
 
 	list_for_each_entry(ipkg, &db->installed.packages, installed_pkgs_list) {
@@ -1436,6 +1430,12 @@ void apk_db_close(struct apk_database *db)
 		close(db->lock_fd);
 	if (db->root != NULL)
 		free(db->root);
+
+	if (db->cache_remount_dir) {
+		do_remount(db->cache_remount_dir, "ro");
+		free(db->cache_remount_dir);
+		db->cache_remount_dir = NULL;
+	}
 }
 
 static int fire_triggers(apk_hash_item item, void *ctx)