CA-141364: Don't ignore errors from libxc on domain build
CA-141364: Don't ignore errors from libxc on domain build

Failures from these calls are fatal and we should not continue with any VM
build (start, resume) operations if these calls return an error.

Signed-off-by: Si Beaumont <a0992b7f1f450b4c7716d34b81a2d6f0877ae11a@citrix.com>

cheng--zhang/xenopsd,johnelse/xenopsd,cheng--zhang/xenopsd,koushikcgit/xenopsd,koushikcgit/xenopsd,simonjbeaumont/xenopsd,euanh/xenopsd,thomassa/xenopsd,koushikcgit/xenopsd,djs55/xenopsd,djs55/xenopsd,thomassa/xenopsd,simonjbeaumont/xenopsd,thomassa/xenopsd,euanh/xenopsd,euanh/xenopsd,djs55/xenopsd,johnelse/xenopsd,johnelse/xenopsd,cheng--zhang/xenopsd,simonjbeaumont/xenopsd