main.c: Fix use-after-free on failed search_fn

When search_fn fails, it must free `r` before `results`, as the former
is assigned based on the latter - otherwise, it would lead to undefined
behaviour.

So far, only memory allocation errors would make search_fn to fail.

main.c

@@ -610,8 +610,8 @@ static int search_fn(const char *const fpath, const struct stat *const sb,
     return 0;
 
 failure:
-    free(results);
     search_result_free(r);
+    free(results);
     return -1;
 }