glu: Fix deprecated conversion from string constant to ‘char*’ warning.

src/glu/sgi/libnurbs/internals/bin.cc

@@ -119,7 +119,7 @@ Bin::adopt()
  */
 
 void
-Bin::show( char *name )
+Bin::show( const char *name )
 {
 #ifndef NDEBUG
     _glu_dprintf( "%s\n", name );

src/glu/sgi/libnurbs/internals/bin.h

@@ -57,7 +57,7 @@ public:
     int			numarcs( void );
     void 		adopt( void );
     void		markall( void );
-    void		show( char * );
+    void		show( const char * );
     void		listBezier( void );
 };