LXC: don't try to mount selinux filesystem when user namespace enabled
LXC: don't try to mount selinux filesystem when user namespace enabled

Right now we mount selinuxfs even user namespace is enabled and
ignore the error. But we shouldn't ignore these errors when user
namespace is not enabled.

This patch skips mounting selinuxfs when user namespace enabled.

Signed-off-by: Gao feng <7e9c653c8ec3abfdd967a0616fd143ca77e7b405@cn.fujitsu.com>

rlaager/libvirt,taget/libvirt,jfehlig/libvirt,nertpinx/libvirt,shugaoye/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,elmarco/libvirt,cbosdo/libvirt,elmarco/libvirt,crobinso/libvirt,eskultety/libvirt,taget/libvirt,agx/libvirt,jardasgit/libvirt,cbosdo/libvirt,olafhering/libvirt,rlaager/libvirt,datto/libvirt,zhlcindy/libvirt-1.1.4-maintain,elmarco/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,eskultety/libvirt,jardasgit/libvirt,olafhering/libvirt,datto/libvirt,andreabolognani/libvirt,agx/libvirt,datto/libvirt,cbosdo/libvirt,jfehlig/libvirt,rlaager/libvirt,jardasgit/libvirt,agx/libvirt,rlaager/libvirt,libvirt/libvirt,VenkatDatta/libvirt,elmarco/libvirt,shugaoye/libvirt,eskultety/libvirt,taget/libvirt,fabianfreyer/libvirt,zhlcindy/libvirt-1.1.4-maintain,fabianfreyer/libvirt,zippy2/libvirt,zippy2/libvirt,eskultety/libvirt,fabianfreyer/libvirt,crobinso/libvirt,olafhering/libvirt,agx/libvirt,zippy2/libvirt,zhlcindy/libvirt-1.1.4-maintain,agx/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,datto/libvirt,nertpinx/libvirt,libvirt/libvirt,cbosdo/libvirt,taget/libvirt,libvirt/libvirt,eskultety/libvirt,crobinso/libvirt,jardasgit/libvirt,cbosdo/libvirt,crobinso/libvirt,zhlcindy/libvirt-1.1.4-maintain,taget/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,datto/libvirt,zhlcindy/libvirt-1.1.4-maintain,shugaoye/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,rlaager/libvirt,libvirt/libvirt,zippy2/libvirt,elmarco/libvirt,shugaoye/libvirt