Fix some warnings in manual tests

Fix:
gestures.cpp:46:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
gestures.cpp:47:5: note: here
gestures.cpp:48:9: warning: this statement may fall through [-Wimplicit-fallthrough=]
gestures.cpp:52:5: note: here
main.cpp: In function 'QByteArray windowsVersionToString(QSysInfo::WinVersion)':
main.cpp:40:12: warning: enumeration value 'WV_CE' not handled in switch [-Wswitch]
...

main.cpp: In function 'QByteArray macVersionToString(QSysInfo::MacVersion)':
main.cpp:68:12: warning: enumeration value 'MV_10_12' not handled in switch [-Wswitch]
...

widget.cpp: In member function 'CustomItem* Widget::checkedItem() const':
widget.cpp:238:12: warning: 'item' may be used uninitialized in this function [-Wmaybe-uninitialized]

Change-Id: I434784e86d127e56b92663cb45eba7d60d8f8eaf
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/manual/qgraphicsitemgroup/widget.cpp b/tests/manual/qgraphicsitemgroup/widget.cpp
index b0e7a47cf8..ba9ed815fa 100644
--- a/tests/manual/qgraphicsitemgroup/widget.cpp
+++ b/tests/manual/qgraphicsitemgroup/widget.cpp
@@ -224,7 +224,7 @@ void Widget::updateUngroupButton()
 
 CustomItem * Widget::checkedItem() const
 {
-    CustomItem *item;
+    CustomItem *item = nullptr;
 
     if (ui->blue->isChecked())
         item = rectBlue;