Mock the function I just added in testing

Author: theotherjimmy

tools/test/build_api/build_api_test.py

@@ -55,6 +55,7 @@ def tearDown(self):
            side_effect=[i % 2 for i in range(3000)])
     @patch('os.mkdir')
     @patch('tools.toolchains.exists', return_value=True)
+    @patch('tools.toolchains.mbedToolchain.dump_build_profile')
     @patch('tools.utils.run_cmd', return_value=("", "", 0))
     def test_always_complete_build(self, *_):
         with MagicMock() as notify: