tint/reader/spirv: Remove stdout spam

Change-Id: I8e38535d32f3e82800740894d5d47256fa926b23
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/120720
Auto-Submit: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>

src/tint/reader/spirv/parser_impl_handle_test.cc

@@ -3886,7 +3886,6 @@ TEST_F(SpvParserHandleTest, SamplerLoadedInEnclosingConstruct_DontGenerateVar) {
            OpFunctionEnd
   )";
     auto p = parser(test::Assemble(assembly));
-    std::cout << assembly;
     EXPECT_TRUE(p->BuildAndParseInternalModule()) << assembly;
     auto fe = p->function_emitter(100);
     EXPECT_TRUE(fe.EmitBody()) << p->error();