From Albert Luaces, typo fixes.

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14883 16af8721-9629-0410-8352-f15c8da7e697

src/osgUtil/Simplifier.cpp

@@ -754,7 +754,7 @@ public:
             if (itr!=_edgeSet.end())
             {
                 // remove the edge from the list, as its positoin in the list
-                // may need to change once its values have been ammended
+                // may need to change once its values have been amended
                 _edgeSet.erase(itr);
             }