customitems examples: adhere to guidelines

They were in a pretty good state already.
This patch simply makes some minor tweaks,
based on our own guidelines for examples.

The tweaks include, but are not limited to:
- PRIVATE linkage
- WIN32 and MACOSX_BUNDLE in qt_add_executable()
- Remove unused #include
- Use qsTr()
- Remove warnings.

Pick-to: 6.5
Change-Id: Ie4d50d4e2134b7b373bdf1ba38779d3052165286
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/examples/quick/customitems/dialcontrol/dialcontrol.qml b/examples/quick/customitems/dialcontrol/dialcontrol.qml
index d30f66fa2c..695ec9fb46 100644
--- a/examples/quick/customitems/dialcontrol/dialcontrol.qml
+++ b/examples/quick/customitems/dialcontrol/dialcontrol.qml
@@ -43,7 +43,7 @@ Rectangle {
                 return
             }
 
-            var desiredPercent = slider.x * 100 / (oldWidth - 32)
+            let desiredPercent = slider.x * 100 / (oldWidth - 32)
             slider.x = desiredPercent * (width - 32) / 100
             oldWidth = width
         }