During startup, the LXC driver uses paths such as

  /.oldroot/var/run/libvirt/lxc/...

to access directories from the previous root filesystem
after doing a pivot_root(). Unfortunately if /var/run
is an absolute symlink to /run, instead of a relative
symlink to ../run, these paths break.

At least one Linux distro is known to use an absolute
symlink for /var/run, so workaround this, by resolving
all symlinks before doing the pivot_root().
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>