Avoid warning on empty expressions

For some reason, Q_UNUSED includes already a semicolon, adding one
on the user side creates an additional empty statement.

Change-Id: I9c5e8fac381345a60792cb75e2938fd53958d3b0
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/vcsbase/vcsbaseclientsettings.cpp

@@ -394,7 +394,7 @@ QVariant VcsBaseClientSettings::keyDefaultValue(const QString &key) const
 
 void VcsBaseClientSettings::readLegacySettings(const QSettings *settings)
 {
-    Q_UNUSED(settings);
+    Q_UNUSED(settings)
 }
 
 } // namespace VcsBase