Remove redundant deprecation disabling in MockTest

I'm not sure these calls to DeprecationDisabler.disable_deprecations
were ever necessary. Currently the relevant deprecation warnings are
only every displayed if the reinstate_undocumented_behaviour_from_v1_9
configuration option is true which is the default. Perhaps this wasn't
always the case and these calls are a vestige of that...? Anyway, they
certainly aren't needed now.

test/acceptance/mock_test.rb

@@ -44,11 +44,9 @@ def test_should_build_string_named_mock_and_explicitly_add_an_expectation_which_
   def test_should_build_symbol_named_mock_and_explicitly_add_an_expectation_which_is_satisfied
     test_result = run_as_test do
       Mocha::Configuration.override(:reinstate_undocumented_behaviour_from_v1_9 => false) do
-        DeprecationDisabler.disable_deprecations do
-          foo = mock(:foo)
-          foo.expects(:bar)
-          foo.bar
-        end
+        foo = mock(:foo)
+        foo.expects(:bar)
+        foo.bar
       end
     end
     assert_passed(test_result)
@@ -109,11 +107,9 @@ def test_should_build_string_named_mock_incorporating_two_expectations_which_are
   def test_should_build_symbol_named_mock_incorporating_two_expectations_which_are_satisifed
     test_result = run_as_test do
       Mocha::Configuration.override(:reinstate_undocumented_behaviour_from_v1_9 => false) do
-        DeprecationDisabler.disable_deprecations do
-          foo = mock(:foo, :bar => 'bar', :baz => 'baz')
-          foo.bar
-          foo.baz
-        end
+        foo = mock(:foo, :bar => 'bar', :baz => 'baz')
+        foo.bar
+        foo.baz
       end
     end
     assert_passed(test_result)