PAGE_SIZE will be a variable value on platforms where it can be
different due to large pages.
And looks like (c) there is no reason for BUF_SIZE == PAGE_SIZE,
so let's keep it as it was, rather than complicating it with dynamic
allocation for the buffer.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>