elm diskselector: Fixed wrong icon duplication. Do not duplicate icon if icon is NULL. This fixes following error message in diskselector.    ERR<30865>: elm_icon.c:761 elm_icon_add() safety check failed: parent == NULL
elm diskselector: Fixed wrong icon duplication. Do not duplicate icon if icon is NULL.
This fixes following error message in diskselector.
   ERR<30865>: elm_icon.c:761 elm_icon_add() safety check failed: parent == NULL

SVN revision: 75847

FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,tasn/elementary,rvandegrift/elementary,FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,tasn/elementary,rvandegrift/elementary,FlorentRevest/Elementary,tasn/elementary,FlorentRevest/Elementary