Remove stdout spam

Change-Id: Iaca6434003a0f10f5b35cce39cf48548f22f9114
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/80843
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>

src/transform/utils/hoist_to_decl_before_test.cc

@@ -267,7 +267,6 @@ TEST_F(HoistToDeclBeforeTest, Array2D) {
   Program original(std::move(b));
   ProgramBuilder cloned_b;
   CloneContext ctx(&cloned_b, &original);
-  std::cout << str(original) << std::endl;
 
   HoistToDeclBefore hoistToDeclBefore(ctx);
   auto* sem_expr = ctx.src->Sem().Get(expr);