PVS-Studio warning V627 for OpenDDS

static void *
initialize (TEST_MALLOC *allocator)
{
  ....
  ACE_ALLOCATOR_RETURN (gap,
                        allocator->malloc (sizeof (256)),
                        0);
  ....
}

This suspicious code was found in OpenDDS project by PVS-Studio static code analyzer.
Warning message is:
V627 Consider inspecting the expression. The argument of sizeof() is the macro which expands to a number. test_position_independent_malloc.cpp 61

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