progs/tests: fix MSVC build.

Signed-off-by: Brian Paul <brianp@vmware.com>

progs/tests/vao-01.c

@@ -124,10 +124,10 @@ static void Init( void )
       exit(2);
    }
 
-   bind_vertex_array = glutGetProcAddress( "glBindVertexArrayAPPLE" );
-   gen_vertex_arrays = glutGetProcAddress( "glGenVertexArraysAPPLE" );
-   delete_vertex_arrays = glutGetProcAddress( "glDeleteVertexArraysAPPLE" );
-   is_vertex_array = glutGetProcAddress( "glIsVertexArrayAPPLE" );
+   bind_vertex_array = (PFNGLBINDVERTEXARRAYAPPLEPROC) glutGetProcAddress( "glBindVertexArrayAPPLE" );
+   gen_vertex_arrays = (PFNGLGENVERTEXARRAYSAPPLEPROC) glutGetProcAddress( "glGenVertexArraysAPPLE" );
+   delete_vertex_arrays = (PFNGLDELETEVERTEXARRAYSAPPLEPROC) glutGetProcAddress( "glDeleteVertexArraysAPPLE" );
+   is_vertex_array = (PFNGLISVERTEXARRAYAPPLEPROC) glutGetProcAddress( "glIsVertexArrayAPPLE" );
 
 
    (*gen_vertex_arrays)( 1, & obj );