vrend: remove message for intentionally unbound sampler state

A debug message is emitted whenever sampler states are applied and a
NULL state pointer is encountered. NULL pointers indicate that the
default state should be used instead, so there's no need to spam with
error messages approx. 1+ times per draw-call.

commit 405a50d ("vrend: cleanup vrend_bind_sampler_states") adds a more
useful debug message at sampler state bind-time when handle is non-zero
and corresponding state object cannot be located.

Fixes: 32c733f ("src/: replace all instances of "fprintf to stderr" with "vrend_printf"")

Signed-off-by: Ryan Neph <ryanneph@google.com>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>

src/vrend_renderer.c

@@ -5866,10 +5866,10 @@ static void vrend_apply_sampler_state(struct vrend_sub_context *sub_ctx,
    bool set_all = false;
    GLenum target = tex->base.target;
 
-   if (!state) {
-      vrend_printf( "cannot find sampler state for %d %d\n", shader_type, id);
+   assert(offsetof(struct vrend_sampler_state, base) == 0);
+   if (!state)
       return;
-   }
+
    if (res->base.nr_samples > 0) {
       tex->state = *state;
       return;