Fix glstuff compilation error

panda/src/glstuff/glGraphicsStateGuardian_src.cxx

@@ -10858,7 +10858,7 @@ upload_texture(CLP(TextureContext) *gtc, bool force, bool uses_mipmaps) {
       gtc->_width = width;
       gtc->_height = height;
       gtc->_depth = depth;
-      gtc->update_data_size_bytes(get_texture_memory_size(gtc));
+      gtc->update_data_size_bytes(get_texture_memory_size(tex));
 
       needs_reload = false;
     }