Fixed error in doxygen comment that was prevent construction of documentation for function dof_ptr.
Fixed error in doxygen comment that was prevent construction of documentation for function dof_ptr.

LimitPointSystems/SheafSystem,LimitPointSystems/SheafSystem,LimitPointSystems/SheafSystem,LimitPointSystems/SheafSystem,LimitPointSystems/SheafSystem,LimitPointSystems/SheafSystem