fix clang build on travis-ci

Author: matlo607

examples/CalcQt/features/step_definitions/CalculatorQtSteps.cpp

@@ -37,11 +37,13 @@ GIVEN("^I just turned on the calculator$") {
     ctx->calculator.move(0, 0);
     ctx->calculator.show();
 #if QT_VERSION >= 0x050000
-    QTest::qWaitForWindowExposed(&ctx->calculator);
+    bool exposed = QTest::qWaitForWindowExposed(&ctx->calculator);
 #else
-    QTest::qWaitForWindowShown(&ctx->calculator);
+    bool exposed = QTest::qWaitForWindowShown(&ctx->calculator);
 #endif
-    QTest::qWait(millisecondsToWait());
+    if (!exposed) {
+        QTest::qWait(millisecondsToWait());
+    }
 }
 
 WHEN("^I press (\\d+)$") {