Tests: Fix environment for test run

Change-Id: I32e491d06d9041b8ba6ad24badd6aa383ba1d163
Reviewed-by: hjk <hjk@qt.io>

tests/manual/shootout/tst_codesize.cpp

@@ -100,6 +100,8 @@ private:
 
 void tst_CodeSize::initTestCase()
 {
+    m_env = QProcessEnvironment::systemEnvironment();
+
     m_qmakeBinary = qgetenv("QTC_QMAKE_PATH_FOR_TEST");
     if (m_qmakeBinary.isEmpty())
         m_qmakeBinary = "qmake";