Doc: move snippet for implicit translation context

The 'sdi' example is a candidate for removal, so point at the
spreadsheet example instead, which is not.

Change-Id: I4405f2421db8be79898a38ca4f3fa1ea5fe0280b
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
(cherry picked from commit 721b4a4b5a8b4e16d50690e0d9ca62725c3ddafb)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

examples/widgets/itemviews/spreadsheet/spreadsheet.cpp

@@ -106,9 +106,11 @@ void SpreadSheet::createActions()
     secondSeparator->setSeparator(true);
 }
 
+//! [implicit tr context]
 void SpreadSheet::setupMenuBar()
 {
     QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
+//! [implicit tr context]
     fileMenu->addAction(printAction);
     fileMenu->addAction(exitAction);
 

examples/widgets/mainwindows/sdi/mainwindow.cpp

@@ -124,11 +124,9 @@ void MainWindow::tile(const QMainWindow *previous)
         move(pos);
 }
 
-//! [implicit tr context]
 void MainWindow::createActions()
 {
     QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
-//! [implicit tr context]
     QToolBar *fileToolBar = addToolBar(tr("File"));
 
     const QIcon newIcon = QIcon::fromTheme("document-new", QIcon(":/images/new.png"));

src/corelib/kernel/qobject.cpp

@@ -2383,7 +2383,7 @@ void QObject::deleteLater()
     translated string is available.
 
     Example:
-    \snippet ../widgets/mainwindows/sdi/mainwindow.cpp implicit tr context
+    \snippet ../widgets/itemviews/spreadsheet/spreadsheet.cpp implicit tr context
     \dots
 
     If the same \a sourceText is used in different roles within the