Initialize member variables

26555== Conditional jump or move depends on uninitialised value(s)

26555== at 0x46A7F2D3: KisToolSelectSimilar::resetCursorStyle() (kis_tool_select_similar.cc:179)

26555== by 0x5BDF99C: KisTool::canvasResourceChanged(int, QVariant const&) (kis_tool.cc:178)

26555== by 0xC0E8302: KoToolBase::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (moc_KoToolBase.cpp:153)

26555== by 0x9417E24: QMetaObject::activate(QObject*, int, int, void**) (in /usr/lib/x86_64-linux-gnu/libQt5Core.so.5.12.0)

26555== by 0xC0E6C42: KoCanvasResourceProvider::canvasResourceChanged(int, QVariant const&) (moc_KoCanvasResourceProvider.cpp:157)

26555== by 0x9417F3E: QMetaObject::activate(QObject*, int, int, void**) (in /usr/lib/x86_64-linux-gnu/libQt5Core.so.5.12.0)

26555== by 0xC0E75A2: KoResourceManager::resourceChanged(int, QVariant const&) (moc_KoResourceManager_p.cpp:141)

26555== by 0xBF2F340: KoResourceManager::notifyResourceChanged(int, QVariant const&) (KoResourceManager_p.cpp:74)

26555== by 0xBF2F9A9: KoResourceManager::setResource(int, QVariant const&) (KoResourceManager_p.cpp:67)

26555== by 0x5A2E1BF: KisCanvasResourceProvider::slotNodeActivated(KisSharedPtr<KisNode>) (kis_canvas_resource_provider.cpp:258)

26555== by 0x5ABA559: KisNodeManager::setView(QPointer<KisView>) (kis_node_manager.cpp:229)

26555== by 0x5DF8619: KisViewManager::setCurrentView(KisView*) (KisViewManager.cpp:490)