rewrite test to correctly test clear method

Clear should not call callbacks because it clear calls
delete_all and then returns self. It should behave the same
as delete_all. This test clarifies the goal of the test and
tests the correct outcome.

activerecord/test/cases/associations/callbacks_test.rb

@@ -150,7 +150,7 @@ def test_has_and_belongs_to_many_remove_callback
                   "after_removing#{jamis.id}"], activerecord.developers_log
   end
 
-  def test_has_and_belongs_to_many_remove_callback_on_clear
+  def test_has_and_belongs_to_many_does_not_fire_callbacks_on_clear
     activerecord = projects(:active_record)
     assert activerecord.developers_log.empty?
     if activerecord.developers_with_callbacks.size == 0
@@ -161,7 +161,7 @@ def test_has_and_belongs_to_many_remove_callback_on_clear
     end
     log_array = activerecord.developers_with_callbacks.flat_map {|d| ["before_removing#{d.id}","after_removing#{d.id}"]}.sort
     assert activerecord.developers_with_callbacks.clear
-    assert_equal log_array, activerecord.developers_log.sort
+    assert_predicate activerecord.developers_log, :empty?
   end
 
   def test_has_many_and_belongs_to_many_callbacks_for_save_on_parent