Fix dead stores in the modelinglib

Found via the clang-static-analyzer

Change-Id: Ic035a88d26b2a096d293133eb4638a090ac5a5c2
Reviewed-by: Jochen Becher <jochen_becher@gmx.de>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/libs/modelinglib/qmt/diagram_scene/items/componentitem.cpp

@@ -358,7 +358,6 @@ void ComponentItem::updateGeometry()
             m_contextLabel->setMaxWidth(maxContextWidth);
         }
         m_contextLabel->setPos(-m_contextLabel->boundingRect().width() / 2.0, y);
-        y += m_contextLabel->boundingRect().height();
     }
 
     updateSelectionMarkerGeometry(rect);