When target file obtained from epoll fdinfo (internally the
kernel keeps only file _number_ inside) we have to check its
identity to make sure it is exactly one which has been added
into epoll engine. The only proper way is to use kcmp syscall.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>