Clarify DiscoveryImplPlatform initialization

Author: mbknust

src/lib/dnssd/platform/tests/TestPlatform.cpp

@@ -156,7 +156,11 @@ test::ExpectedCall commissionableLargeEnhanced = test::ExpectedCall()
 class TestDnssdPlatform : public ::testing::Test
 {
 public:
-    static void SetUpTestSuite() { VerifyOrDie(chip::Platform::MemoryInit() == CHIP_NO_ERROR); }
+    static void SetUpTestSuite()
+    {
+        ASSERT_EQ(chip::Platform::MemoryInit(), CHIP_NO_ERROR);
+        // DiscoveryImplPlatform is initialized inside testcase code
+    }
     static void TearDownTestSuite()
     {
         DiscoveryImplPlatform::GetInstance().Shutdown();