advapi32/tests: Don't test the contents of an uninitialized buffer.

dlls/advapi32/tests/service.c

@@ -685,7 +685,7 @@ static void test_get_servicekeyname(void)
        GetLastError() == ERROR_IO_PENDING /* W2K */ ||
        GetLastError() == 0xdeadbeef       /* NT4, XP, Vista */,
        "Expected ERROR_SUCCESS, ERROR_IO_PENDING or 0xdeadbeef, got %d\n", GetLastError());
-    todo_wine
+    if (ret)
     {
         ok(lstrlen(servicename) == tempsize/2,
            "Expected the buffer to be twice the length of the string\n") ;