Fix change-of-sign warnings caught by ICC 17

error #68: integer conversion resulted in a change of sign

Change-Id: I33dc971f005a4848bb8ffffd1475ee53d394acf6
Reviewed-by: Andrew Knight <andrew.knight@intopalo.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp

@@ -88,7 +88,7 @@ void QEglFSKmsEglDeviceScreen::waitForFlip()
 
         qCDebug(qLcEglfsKmsDebug, "Setting mode");
         int ret = drmModeSetCrtc(device()->fd(), output().crtc_id,
-                                 -1, 0, 0,
+                                 uint32_t(-1), 0, 0,
                                  &output().connector_id, 1,
                                  &output().modes[output().mode]);
         if (ret)

src/plugins/platforms/vnc/qvnc.cpp

@@ -41,6 +41,7 @@
 #include "qvncclient.h"
 #include "QtNetwork/qtcpserver.h"
 #include "QtNetwork/qtcpsocket.h"
+#include <qendian.h>
 #include <qthread.h>
 
 #include <QtGui/qguiapplication.h>
@@ -554,7 +555,7 @@ void QVncClientCursor::write(QVncClient *client) const
                                  htons(cursor.height()) };
         socket->write((char*)tmp, sizeof(tmp));
 
-        const quint32 encoding = htonl(-239);
+        const qint32 encoding = qToBigEndian(-239);
         socket->write((char*)(&encoding), sizeof(encoding));
     }