[Nel] Fix for code/nel/src/3d/flare_model.cpp

[Aurelien.Delaitre]

Hi,

NL3D::CFlareModel::traverseRender() calls
NL3D::CViewport::getX/Y/Height/Width but these methods don't exist in
CViewport. There is a getValues method instead. Here is the error log:

    'NL3D::CFlareModel::traverseRender()': 
 flare_model.cpp:117: no matching function for call to
'NL3D::CViewport::getX()' 
 flare_model.cpp:117: no matching function for call to  
    `NL3D::CViewport::getWidth()' 
 flare_model.cpp:118: no matching function for call to
`NL3D::CViewport::getY()' 
 flare_model.cpp:118: no matching function for call to  
    `NL3D::CViewport::getHeight()' 
 flare_model.cpp:81: warning: statement with no effect 

NL3D::CViewport::getX/Y/Height/Width must be added or else methods of
CFlareModel must use NL3D::CViewport::getValues().

  A.