Fix variable names in MaliitKeyboard::Renderer implementation
Fix variable names in MaliitKeyboard::Renderer implementation

RevBy: Jon Nordby
extendedRoot => extended_root
extendedSurface => extended_surface

maliit/plugins,RHawkeyed/plugins,develersrl/maliit-demo-qml,KDE/plasma-maliit-plugins,develersrl/maliit-demo-qml,RHawkeyed/plugins,develersrl/maliit-demo-qml,maliit/plugins,RHawkeyed/plugins,KDE/plasma-maliit-plugins,RHawkeyed/plugins,develersrl/maliit-demo-qml,maliit/plugins,KDE/plasma-maliit-plugins,KDE/plasma-maliit-plugins,maliit/plugins,RHawkeyed/plugins