Doc: Fix small typo

Task-number: QTBUG-36981

Change-Id: I0663aa58def0bda7601fad4e0c10362a562b0290
Reviewed-by: Nico Vertriest <nico.vertriest@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

doc/src/snippets/code/doc_src_i18n.cpp

@@ -165,7 +165,7 @@ void Clock::setTime(const QTime &time)
 //! [12]
 void MyWidget::changeEvent(QEvent *event)
 {
-    if (e->type() == QEvent::LanguageChange) {
+    if (event->type() == QEvent::LanguageChange) {
         titleLabel->setText(tr("Document Title"));
         ...
         okPushButton->setText(tr("&OK"));