tst_Moc: restore signals/slots/emit to the Q_UPPERCASE values

The previous definition of signals does not need to be "public". It may
have been something else.

Change-Id: Id69569111e7d4e619e22ffff144b4855e6acdbef
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

tests/auto/tools/moc/no-keywords.h

@@ -70,9 +70,9 @@ private:
     double slots;
 };
 
-#define signals public
-#define slots
-#define emit
+#define signals Q_SIGNALS
+#define slots Q_SLOTS
+#define emit Q_EMIT
 #undef QT_NO_KEYWORDS
 
 #endif // NO_KEYWORDS_H