Fix typo (bug 12552).


git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/doc/registry/public/api@27655 e7fa87d3-cd2b-0410-9028-fcbf551c1848
git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/doc/registry/public/api@27684 e7fa87d3-cd2b-0410-9028-fcbf551c1848