glx cannot convert type

[doug]

Running on ubuntu linux 64-bit, the command 'go install ./gl-core/3.3/gl', returns the following error:

procaddr/glx/glx.go:10: cannot convert _Cfunc_CString(name) (type *_Ctype_char) to type *_Ctype_GLubyte

[errcw]

I verified that this fix allows the library to compile but was unable to verify it works as expected (you can see how this ended up broken in the first place)—please let me know if this fix is insufficient.