log: duplicate a file descriptor
log: duplicate a file descriptor

When we use libct from other languages, a life time of fd
can depend on a language.

Signed-off-by: Andrew Vagin <74c05afa918858348d6db8037d82fa8124870113@openvz.org>

xemul/libct,xemul/libct,avagin/libct,xemul/libct,xemul/libct,hallyn/libct,hallyn/libct,avagin/libct,hallyn/libct,avagin/libct