io: Add __splice_data helper

I need it for debug purpose.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
read: Print section length on debug

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
net: Convert routes

Main trick: OpenVZ kernel converts everything but in CRIU we ignore
cacheinfo, so drop such routes when converting.

I added FIXME there so we won't miss this piese of code if needed.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
net: Allow venet to be present in dump

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>