Fix 'Non-static class member "yy_lp" is not initialized in this constructor nor in any functions that it calls".
Fix 'Non-static class member "yy_lp" is not initialized in this constructor nor in any functions that it calls".

Coverity CID 126893:  Uninitialized members  (UNINIT_CTOR)

tomasthoresen/osg,scrawl/osg,marchelbling/osg,scrawl/osg,openscenegraph/osg,scrawl/osg,openscenegraph/osg,tomasthoresen/osg,jtorresfabra/osg,tomasthoresen/osg,openscenegraph/osg,openscenegraph/osg,marchelbling/osg,marchelbling/osg,jtorresfabra/osg,jtorresfabra/osg,marchelbling/osg,scrawl/osg,jtorresfabra/osg,tomasthoresen/osg