Merge pull request #4429 from shuujii/move-mrb_gc_arena_restore-into-loop-in-mrb_file_s_chmod

Move `mrb_gc_arena_restore` to inside the loop in `mrb_file_s_chmod`

mrbgems/mruby-io/src/file.c

@@ -423,9 +423,9 @@ mrb_file_s_chmod(mrb_state *mrb, mrb_value klass) {
       mrb_sys_fail(mrb, utf8_path);
     }
     mrb_locale_free(path);
+    mrb_gc_arena_restore(mrb, ai);
   }
 
-  mrb_gc_arena_restore(mrb, ai);
   return mrb_fixnum_value(argc);
 }