patch 9.0.0990: callback name argument is changed by setqflist()

Problem:    Callback name argument is changed by setqflist().
Solution:   Use the expanded function name for the callback, do not store it
            in the argument. (closes #11653)
diff --git a/src/time.c b/src/time.c
index 891a9f4..efdad69 100644
--- a/src/time.c
+++ b/src/time.c
@@ -908,6 +908,8 @@
     else
     {
 	set_callback(&timer->tr_callback, &callback);
+	if (callback.cb_free_name)
+	    vim_free(callback.cb_name);
 	rettv->vval.v_number = (varnumber_T)timer->tr_id;
     }
 }