intel: Remove another renderbuffer allocation path.

Now there's the thing that CALLOCs and sets up window system vtable,
and the thing that CALLOCs and sets up user renderbuffer vtable.  The
user renderbuffer vtable gets replaced later by
intel_renderbuffer_update_wrapper for wrapped renderbuffers (things
with name == ~0).

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/drivers/dri/intel/intel_fbo.c

@@ -619,20 +619,16 @@ intel_renderbuffer_wrap_miptree(struct intel_context *intel,
                                 GLenum internal_format)
 
 {
-   const GLuint name = ~0;   /* not significant, but distinct for debugging */
    struct gl_context *ctx = &intel->ctx;
+   struct gl_renderbuffer *rb;
    struct intel_renderbuffer *irb;
 
    intel_miptree_check_level_layer(mt, level, layer);
 
-   irb = CALLOC_STRUCT(intel_renderbuffer);
-   if (!irb) {
-      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glFramebufferTexture");
+   rb = intel_new_renderbuffer(ctx, ~0);
+   irb = intel_renderbuffer(rb);
+   if (!irb)
       return NULL;
-   }
-
-   _mesa_init_renderbuffer(&irb->Base, name);
-   irb->Base.ClassID = INTEL_RB_CLASS;
 
    if (!intel_renderbuffer_update_wrapper(intel, irb,
                                           mt, level, layer,