Fixed typo.

mastoapi.c

@@ -2595,7 +2595,7 @@ int mastoapi_put_handler(const xs_dict *req, const char *q_path,
                 if (valid_status(timeline_get_by_md5(&snac, md5, &msg))) {
                     const char *content = xs_dict_get(args, "status");
                     xs *atls = xs_list_new();
-                    const char *f_content = not_really_markdown(content, &atls);
+                    xs *f_content = not_really_markdown(content, &atls);
 
                     /* replace fields with new content */
                     msg = xs_dict_set(msg, "sourceContent", content);