qt: Clarify some comments

Signed-off-by: Wladimir J. van der Laan <laanwj@gmail.com>

src/qt/bitcoin.cpp

@@ -516,14 +516,14 @@ void BitcoinApplication::initializeResult(bool success)
         QTimer::singleShot(100, paymentServer, SLOT(uiReady()));
 #endif
     } else {
-        Q_EMIT splashFinished(window);
-        quit(); // Exit main loop
+        Q_EMIT splashFinished(window); // Make sure splash screen doesn't stick around during shutdown
+        quit(); // Exit first main loop invocation
     }
 }
 
 void BitcoinApplication::shutdownResult()
 {
-    quit(); // Exit main loop after shutdown finished
+    quit(); // Exit second main loop invocation after shutdown finished
 }
 
 void BitcoinApplication::handleRunawayException(const QString &message)