Run API check to assert xfrm modules
Run API check to assert xfrm modules

- When docker is run inside a container, the infrastructure
  needed by modprobe is not always available, causing the
  xfrm module load to fail even when these modules are already
  loaded or builtin in the kernel.
- In case of probe failure, before declaring the failure,
  run an API check by attempting the creation of
  a NETLINK_XFRM socket.

Signed-off-by: Alessandro Boch <5bd2eb5b6f60921d9a2b9cb6a0a86bb947f3d361@docker.com>

bearstech/moby,Mokolea/docker,konstruktoid/docker-upstream,bearstech/moby,AkihiroSuda/docker,yosifkit/docker,mahak/docker,bearstech/moby,moby/moby,moby/moby,nawawi/docker,nawawi/docker,flavio/docker,jameszhan/docker,trebonian/docker,gnailuy/docker,nawawi/docker,vdemeester/docker,jthelin/docker,thaJeztah/docker,nalind/docker,Mokolea/docker,nawawi/docker,Ramzec/docker,moul/docker,moul/docker,paralin/docker,gnailuy/docker,vdemeester/docker,nalind/docker,trebonian/docker,mahak/docker,yosifkit/docker,konstruktoid/docker-upstream,cpuguy83/docker,yosifkit/docker,nalind/docker,jimjag/docker,thaJeztah/docker,moul/docker,gnailuy/docker,vdemeester/docker,trebonian/docker,flavio/docker,thaJeztah/docker,Mokolea/docker,konstruktoid/docker-upstream,Ramzec/docker,nalind/docker,paralin/docker,docker/docker,docker/docker,djs55/docker,yosifkit/docker,mahak/docker,AkihiroSuda/docker,gnailuy/docker,moul/docker,cpuguy83/docker,jimjag/docker,jthelin/docker,thaJeztah/docker,cpuguy83/docker,flavio/docker,Ramzec/docker,trebonian/docker,mahak/docker,flavio/docker,docker/docker,Ramzec/docker,AkihiroSuda/docker,jimjag/docker,jameszhan/docker,jimjag/docker,moby/moby,paralin/docker,Mokolea/docker,moby/moby,bearstech/moby,jameszhan/docker,konstruktoid/docker-upstream,AkihiroSuda/docker,cpuguy83/docker,djs55/docker,djs55/docker,paralin/docker